Home of high power coatings and optics
LASEROPTIK GmbH Horster Str. 20 D-30826 Garbsen Germany Phone +49(0) 5131 4597 0 Fax +49(0)5131 4597 20 [email protected]
www.laseroptik.de Home of high power coatings and optics Catalog 2017 II back to Contents
LASEROPTIK at a glance
• Location: Garbsen (Hanover), Germany • Founded: 1984 • Employees: > 80
• Coating machines: 33 (10 IBS) • Techniques: TE, EBE, IAD, IP, MS, IBS, ALD • ISO 9001:2015 certified • 24h coating service with LASEROPTIK EXPRESS • > 1,200 coatings available on LOOP, the LASEROPTIK Online Portal
• Ø 150,000 coated optics / year
Home of high power coatings and optics III
Contact
Senior coating manager and designer Werner Moorhoff [email protected] Tel.: +49 (0) 5131 / 4597-12
Operations and coating design Dr. Michael Kennedy [email protected] Tel.: +49 (0) 5131 / 4597-52
AR coatings and LOOP Heiko Hänsel [email protected] Tel.: +49 (0) 5131 / 4597-17
Ion beam sputtering and dispersive mirrors Tobias Groß [email protected] Tel.: +49 (0) 5131 / 4597-414
Stock components and coating design Dr. Christoph Gödeker [email protected] Tel.: +49 (0) 5131 / 4597-54
Operations scheduling Maic Holst [email protected] Tel.: +49 (0) 5131 / 4597-34
Magnetron sputtering and spaceborne optics Martin Ebert [email protected] Tel.: +49 (0) 5131 / 4597-30
President Dr. Wolfgang Ebert [email protected] Tel.: +49 (0) 5131 / 4597-0
Founder Dr. Johannes Ebert [email protected] Tel.: +49 (0) 5131 / 4597-0 IV back to Contents
Starting a request
For a quotation we need to know at least the following information:
1. Substrates:
• Material, quantity and size______• For curved surfaces: radius of curvature and used aperture ______• Supplied by customer or LASEROPTIK?______
2. Coating:
• Wavelengths, angle of incidence and polarization______• Surface to be coated (both, plane, curved, wedged side?)______
Helpful information, if available:
3. LIDT:
• Beam radius/ profile______• Pulsed: J/cm², repetition-rate and pulse duration______• cw: KW per cm beam diameter______
If not mentioned otherwise we will offer for
• Standard laser power ______• Normal environmental conditions (use in air at room temperature)_____
4. Your contact data:
• Name ______• Name of company______• Department/institute______• Address______• Phone number______• E-mail address______
LASEROPTIK GmbH Horster Str. 20 D-30826 Garbsen Germany Phone +49 (0) 5131 4597 0 Fax +49 (0) 5131 4597 20 [email protected]
www.laseroptik.de Welcome
LASEROPTIK focusses on the development and production of optical coatings and components for high power laser applications in industry, medicine and research.
For more than 30 years LASEROPTIK's number one objective is to help our customers build better lasers by providing ex- cellent coated optics.
This catalog provides you with broad information about the background of our company, our coatings and substrates, and about what LASEROPTIK is able to do for you in the field of thin film coatings and laser optics.
As these 124 pages cannot give the answer to every ques- tion please contact us and we will find a solution to your needs together.
Dr. Johannes Ebert Dr. Wolfgang Ebert 2
Contents
LO at a glance go to page II Contact go to page III Starting a request go to page IV Welcome go to page 1 Special services go to page 4 Express go to page 4 LOOP go to page 5
Coating guide
Glossary go to page 8 Main types go to page 8 AR go to page 9 HR go to page 9 PR go to page 10 Filter go to page 10 Polarizer go to page 11 Variables go to page 11 Thin film basics go to page 12 The history of coatings go to page 12 Bases of calculation go to page 13 Number of layers go to page 14 HR standards go to page 15 Tips and tricks go to page 18 Production methods go to page 20 Overview coating technologies go to page 20 Comparision go to page 21 ALD go to page 22 EBE go to page 23 IAD go to page 24 IP go to page 25 MS go to page 26 IBS go to page 27
Coatings
VUV/Excimer 120-179 nm go to page 30 UV/Excimer 180-379 nm go to page 32 VIS 380-779 nm go to page 34 NIR 780-1029 nm go to page 36 NIR 1030-1064 nm go to page 38 NIR 1030-1064 nm / Combinations of harmonics go to page 40 NIR 1065-2500 nm go to page 42 MIR > 2500 nm go to page 44 3
Polarizer go to page 46 Variables go to page 48 Variable Attenuators go to page 48 Gradient Output Couplers and Filters go to page 50 Reflection Filters go to page 52 Metal coatings go to page 54 OPO coatings go to page 56 Multi-line coatings go to page 58 Dispersive coatings go to page 60 Low GDD mirrors go to page 62 GTI mirrors go to page 64 Chirped mirrors and matched pairs go to page 66 Partial Reflectors go to page 69 OPO coatings go to page 70 Others go to page 71 Coatings on special substrates go to page 72 Crystals, wafers and metals go to page 72 Fibers, glass cells and UHV windows go to page 73 Large optics go to page 74 Coatings for special applications go to page 75 Extremely low loss laser optics go to page 75 Spaceborne / airborne optics go to page 76 Harsh environments / optimizing flatness go to page 77
Substrates
Production of substrates go to page 80 Tolerances for substrates go to page 82 Standard substrates go to page 86 Characteristics and transmission curves go to page 86 Group Velocity Dispersion (GVD) go to page 94 Reflection of an uncoated surface go to page 95 Stock substrates go to page 96 Material refractive indices go to page 96 Plane windows go to page 97 Wedged, large wedges, elliptical go to page 98 Rectangular, square go to page 99 Plano-concave go to page 100 Plano-convex go to page 101 Zero lenses, cavity lenses go to page 102 Cylindrical lenses, prisms go to page 103 Plane-parallels, etalons go to page 104 CaF2, MgF2, ZnSe, Sapphire, YAG go to page 105
About us
Production flow go to page 108 Substrate cleaning go to page 110 Measuring methods for laser optics go to page 112 Laser Induced Damage Threshold (LIDT) go to page 114 History go to page 118 Appendix go to page 120 Abbreviations go to page 120 Helpful formulas go to page 121 Index go to page 122 References go to page 123 Final questions go to page 124 4 back to Contents
Waiting for the job – for those, who can’t wait.
Get your substrates and coatings the easy, secure and fast way!
We keep a stock of standard substrates and a coating ma- chine for customers who need a very fast turnaround. For this we add an EXPRESS surcharge to your invoice.
You can send us your substrates or you can choose from the large LASEROPTIK substrate stock.
The following three options are available:
LASEROPTIK EXPRESS 24h: An EXPRESS 24h time slot starts on any working day at 9 a.m. (CET) and ends at 9 a.m. (CET) on the following working day. At the end of the slot the substrates are ready for shipment. For coating of both sides we need two slots. LASEROPTIK EXPRESS SAFE: EXPRESS SAFE means we will deliver within 1-2 weeks after an order has been confirmed or, in case of customer owned substrates, after receiving the substrates. LASEROPTIK EXPRESS EXTRA: Special substrates (Fused Silica) which cannot be delivered from the LASEROPTIK substrate stock will be manufactured on customer demand.
Thanks to special arrangements with selected substrate suppliers we can realize a turn-around time of just 3 weeks, including the coating.
In addition to the EXPRESS coating machine we currently use 32 machines partly with sputter technique or ion assistance. Please ask for available time slots. 5
www.laseroptik.de/loop Configure and buy your laser optics online!
LOOP is the name of our LASEROPTIK Online Portal. LOOP gives you online access to a selection of more than 1,200 coatings and 370 standard substrates out of our data base stock with 18,000 different coating designs and 7,000 own substrates.
The benefits of LOOP: • Configurator & shop • Find coatings (B-articles) and substrates (S-articles). • Configure your own optics. • Send your request online. • Order stock components online.
1) Choose 2) Select substrate Create your own optic your coatings or specify your own one or find stock components
front rear + =
B -article S -article L -article
Find your coating type in the glossary and/or search directly by wavelength. Every coating is specified by a computed curve and tolerances. If available, ready coated stock components are listed below the coating runs.
If you do not find exactly what you are looking for, take the best matching article and specify your additional needs. We will offer you an optimized coating or substrate. back to Contents Coating guide
Glossary of coating types Thin film basics Production methods 8 back to Contents Coating guide
Glossary Main types
AR Anti-Reflection Coating page 9 Minimizes surface reflection of substrates for highest transmission, coated on both sides, used as - window or, to minimize back side reflection of beam splitters, used as - rear side coating
HR High Reflection Coating page 9 for highest reflection, used as - cavity mirror - full reflector - bending mirror also available as - metallic mirror
PR Partial Reflection Coating page 10 for splitting or reducing the incoming light, used as - partial reflector, - output coupler, - attenuator, - beam splitter, also available as - non polarizing beam splitter Filter HR / PR + AR Coating page 10 Combination of AR and HR or PR coatings for separating wave- lengths, used as - long / short wave pass - steep edge filter - band pass / interference filter - notch / negative filter - dichroic filter - harmonic beam separator or for combining laser beams, used as - beam sampler - combining mirror - pump mirror
Polarizer Polarizer page 11 Separates the polarizations, coated on plates for - thin film polarizer (TFP) also available for - cube polarizer - broadband polarizer works also as - polarization sampler
Variable Attenuator page 11, 48 Variables Gradient Coating for changing the transmission / reflection ratio with the angle, used as - variable attenuator or with the beam position used as - gradient output coupler - gradient attenuator - gradient pass filter - gradient interference filter 9 Glossary
AR : Anti-Reflection HR : High Reflection Minimizes surface reflection Maximizes surface reflection
Types Types
VAR HR Single AR Coating Single HR Coating Lowest reflection for one sin gle Highest reflection for one single wavelength or a narrow band wavelength or a narrow band
Examples on page 31, 39, 45 Examples on page 31, 35, 37, 45
DAR DHR Double AR Coating Double HR Coating Lowest reflection, optimized Highest reflection, optimized for two wavelengths for two wavelengths, also avai - lable as HR + adjusting layer
Examples on page 33, 40 Examples on page 33, 39, 40
TAR BBHR Triple AR Coating Broadband HR Coating Lowest reflection, optimized Highest reflection, optimized for three wavelengths for a broadband wavelength range Examples on page 40, 41 Examples on page 33, 35
BBAR MHR Broadband AR Coating Multiple HR Coating Lowest reflection, optimized Combination of HR types for a broadband wavelength range Examples on page 14, 37 Examples on page 40, 41
MAR WHR Multiple AR Coating Wide Angle HR Coating Combination of AR types Highest reflection, optimized for a wide angle of incidence (e.g. 0-45°), also available for a Examples on page 43, 57 broadband wavelength range Examples on page 33, 39
WAR Metal Wide Angle AR Coating Metal Coatings Optimized for a wide angle of Achieve high reflection values incidence (e.g. 0-45°), also over a broad wavelength range. available for a broadband Typical coatings: Ag, Au, Al wavelength range Examples on page 35 Examples on page 31, 54, 55
For HR coatings with areas of high transmission see coating type "Filter" (HR/PR + HT combined), page 10. 10 back to Contents Coating guide
+
PR : Partial Reflection Filter Splits or reduces incoming light Separates or combines wavelengths
Types Types PR with fixed reflection/transmission ratio PR LP Single PR Coating Long Wave Pass Coating Constant reflection / trans- HR for one single wavelength mission for one single wave- or a narrow band and HT length or a narrow band for a longer wavelength or Examples on page 14, 31, 33 band, also available as Partial Examples on page 37, 40, 43, 57 Reflector
DPR SP Double PR Coating Short Wave Pass Coating Constant reflection / trans- HR for one single wavelength mis sion for two wavelengths, or a narrow band and HT for a ratio can be optimized separa - shor ter wavelength or band, tely Examples on page 41 al so available as Partial Re - Examples on page 39, 40, 41, 43 flector
BBPR NF Broadband PR Coating Notch Filter Coating Constant reflection / transmis- HR for one single wavelength sion for a broadband wave- or a narrow band and HT for length range a shorter and longer wave- Examples on page 35, 45, 59 length or band, also availa ble Examples on page 40, 41, 57 as Partial Reflector
PR changes reflection/transmission ratio with AOI MP Multi Pass Coating VA Combination of several HR Variable Attenuator and HT wavelength areas, Transmission can be varied also avai l able as Partial Reflec- continuously by changing the tor Examples on page 40, 59 AOI (e.g. 0-45°), also available as Inversely Examples on page 33, 43, 48, 49 Variable Attenuator (IVA) BP Band Pass Coating Selecting a small wavelength PR changes reflection/transmission ratio area, sometimes also known with beam position as IF (Interference Filter), FWHM of some tens of nm Examples on page 37, 43 GOC down to < 1 nm, sputtered Gradient Output Coupler coating Transmission can be varied continuously by shifting a rec- tangular plate across the beam REF (right-middle-left position) Examples on page 39, 50, 51 Reflection Filter Coating Scanning and selecting a small wavelength area by tilting 4 reflection filter plates simul - For PR coatings with areas taneously. No change in the Examples on page 52, 53 of high transmission see final beam direction coating type "Filter". 11 Glossary
Polarizer Variables Separates or combines the polarizations Change transmission / reflection with the angle or the beam position Types Types
TFP VA Thin Film Polarizer Variable Attenuator Separates s- from p-polarized Transmission can be varied light, effective on a plate with continuously by changing the a fixed AOI, available from 45° AOI (e.g. 0-45°), also available to 74°, commonly used with Examples on page 33, 39, 46, 47 as Inversely Variable Attenua- Examples on page 33, 43, 48, 49 Brewster angle tor (IVA)
CP GOC T λ Cube Polarizer Coating Gradient Output Coupler 1 Separates s- from p-polarized Transmission can be varied left right light, effective inside a cube continuously by shifting a middle made out of two prisms, com- rectangular plate across the λ monly with AOI = 45° Examples on page 46, 47 beam (right-middle-left Examples on page 39, 50, 51 position)
BBPOL Broadband Polarizer GP λ Separates s- from p-polarized T Gradient Pass Coating 1 light for a broadband range, By shifting a rectangular plate effective on a plate or inside a across the beam, the incoming left right λ cube with a fixed AOI Examples on page 46, 47 light passes through (right po- Examples on page 50, 51 sition) or will be blocked (left position), shown as Gradient Short Pass GSP, also available as Gradient Long Pass GLP
GNF Gradient Notch Filter λ λ By shifting a rectangular plate T across the beam, the band 1 1 λ around 1 passes through left right (right position)λ or will be Examples on page 50, 51 blocked (left position) and re- versely for 2 λ
GIF Gradient Interference Filter λ λ T By shifting a rectangular plate 1 2 across the beam (left-right po- sition), various wavelengths left right λ can be selected, e.g. for fast Examples on page 50, 51 external change of multiline noble gas ion lasers 12 back to Contents Coating guide
Thin film basics The history of coatings
A glance into the past – with a glimpse into for a broad application range. However, as a the future result of their microstructure the thin films have a few disadvantages. Some of these The history of modern optical coating starts problems can be solved by advanced (though somewhere in the early part of the last century more expensive) deposition technologies like with the advent of high vacuum technology, the follo wing. one basic necessity for thin film deposition. Credit for the design of the first high va cuum Ion Assisted Deposition IAD (page 24) introdu - pump (mercury-vapour condensation pump) ced by the well-known Ebert-gun was a first ap- belongs to Wolfgang Gaede, who filed a Ger- proach to reduce the porosity of the coatings. man patent application in 1907. Using this But it was suitable for small facilities only. technique Robert Wichard Pohl produced thin Newer Kaufman-ion sources were able to stri ke Dr. Johannes Ebert silver films for Fabry-Perot applications two large areas. The drawback of these ion sour ces with an early version of the years later. is their filament, because tungsten is co-eva po- “Ebert-gun” rated and the coating thickness is limited by In 1934 Gerhard Bauer deposited films of alkali the life time of the filaments. The new ion ac- halides and noted their low reflection on quartz celerator of Loeb supported by a gas discharge substrates. Only one year later Alexander Sma - in magnetic fields was constructed for satellite kula introduced this discovery into the produc- navigation and was working sufficiently first as tion at Zeiss-Jena. Bauer recognized that his an ion sour ce in IAD and later in our IBS films were less than perfectly dense, but were plants. sufficient enough for the most optical instru- ments from camera to photocopier. Ion Plating IP (page 25) delivers very hard lay- ers due to high ion impact during deposition, However, increased sophistication of optical comparable with coatings made by Magnetron instruments reinforced the search for high Sputtering MS (page 26). Both methods can be quality optical coatings. In 1985 using an elec- used for applications where no porosity and tron microscope Karl H. Guenther could show high hardness as protection against particle the columnar structure of evaporated films. impact are demanded. Voids running parallel to the columns contri bu - te significantly to the undesirable qualities of Ion Beam Sputtering IBS (page 27) is a low rate the films. When compared to their bulk materi- process which gives the highest layer quality: als evaporated films are softer, weaker, less On super polished surfaces a reflectivity of dense, and chemically less stable. They show 99.999% can be realized with absorption and internal stress and absorb more gases and wa- scatter losses lower than 10 ppm. Additionally ter. Optically they have lower refractive indices, we developed the IBS method for 2 m long higher extinction coefficients and increased substrates in order to meet the needs of the scatter. producers for semiconductors and flat panel displays. Using standard techniques like Thermal Evapo- ration TE and Electron Beam Evaporation EBE LASEROPTIK is ready for the future! (pa ge 23) cost effective coatings can be made
TEM (Transmission Electron Micro scopy) from an IBS band- pass coa ting with amorphous structure 13 Thin film basics
Bases of calculation
Light falls from a medium (n1) onto a thin film (n2) which is laying on a substrate (n3). At each interface one part oft the light will be reflected n1 and a se cond transmitted. Every part can be calculated by the Fresnel equations. For the in- terface n1/n2 you get: n2
For the s-polarization: 2 n3 N cos –N2cos Rs = ———————————1 α β ( N1cos + N2cos ) α β 2 2N1cos Ts = ———————————α The reflection becomes zero for a wavelength ( N1cos + N2cos ) by using a /4-thick monolayer and normal in-λ α β λ cidence__ if the medium is air (n1 = 1) and For the p-polarization: n2 = √n3. This is the easiest way to produce an 2 anti-reflection coating. For substrates where it N2cos –N cos Rp = ———————————α 1 β is not possible to find a coating material with (N2cos + N1cos ) α β matching refractive index you need more layers 2N cos 2 (page 14). Tp = ———————————1 α ( N2cos + N1cos ) α β If more than one layer is deposited the descri - bed process occurs at every interface between N1 = n1 + ik1 ; N2 = n2 + ik2 are the complex in- the layers and the total mathematical calcula- dices of refraction, the extinction coefficients tion becomes more difficult but it is still solv- k1 and k2 relate to absorption. able.
is the angle of incidence, the angle of re- The most effective way to get a high reflective αfraction and can be calculatedβ using Snell’s coating for the wavelength is to stack alter- λ law: N1sin = N2sin nately two different coating materials with a α β. layer thickness of /4 each. With an increasing With normal incidence ( = 0°) and zero ab- number of layer pairsλ the reflection will grow sorption the terms becomeα very simple: up steadily to 100%, only limited by the los ses n –n 2 4n n through absorption and scattering, while the R = —————1 2 ; T = —————1 2 transmission falls down to 0% (page 14). 2 ( n1 + n2 ) (n1 + n2) One frequently asked question is: How thick is All reflected parts and the transmitted parts a coating? To give you an estimation: A normal will interfere. The conditions for interfe rence human hair has a thickness of about 50-100 depend on the optical path difference OPD. µm, a dielectric mirror coating HR 1064 nm/0° For the reflected parts: OPD = 2n2dcos ; has about 5 µm and an EAR 248 nm/0° about where d describes the phy sical thicknessβ of 0.05 µm. the layer.
The interference for a wavelength will be constructive for OPD = m and destructiveλ for 1 λ OPD = (m+ ⁄2) ; (m = 0,1,2,3,…) λ The same formulas can be used for the inter- face n2/n3. So, the total reflected and transmit- On the following pages you will ted light can be calculated by the angle of inci- find some more elementary basics dence, refractive indices and film thickness. of thin film coatings. 14 back to Contents Coating guide
Number of layers
Anti-Reflection coatings (AR) 10 Number of layers
R % Substrate: FS A simple single layer (EAR) decreases the natural reflection of 8 an uncoated surface, best if the refractive index of the layer is 7 near to the square root of the index of the substrate. For Fused 6 Silica (FS) no coating material can be found which fits perfectly. 5 The best matching material is MgF2. BBAR1 uncoated 4 By using two layers of different coating materials the reflection 3 can be minimized for one single wavelength (VAR). EAR 2 BBAR 3 BBAR 2 VAR Anti-reflection coatings even for broadband areas (BBAR) can 1 be realized through an increased number of layers. The larger 0 the bandwidth the higher the achievable reflection. 400 500 600 700 800 900 1000 nm 1200 Some different anti-reflection coatings on FS with AOI = 0°.
Partial Reflectors (PR) 100 Number of layers T % Most PR coatings are produced by alternatively applying layers 80 of two distinct coating materials with different refractive in- 70 dices. 60 By increasing the number of layers the transmission decreases 50 and the reflection increases. 40 30 You can achieve any transmission value by changing the thick- ness of some of the layers. 20 10 0 900 950 1000 1050 1100 1150 1200 nm 1300
The transmission curves of different numbers of layers (n = 1,3,5,…17) for 1064 nm /0°.
100 High Reflectors (HR) R % HR1 HR2 HR3 BBHR Number of layers 80 70 To reach high reflection over a broad wavelength area you have to increase the number of layers. An easy way is to stack single 60 HR systems on each other. The HR system for the most critical 50 wavelength (with the highest laser power and highest reflec- 40 tion) has to be on top. 30 20 10 0 600 700 800 900 1000 1100 nm 1200
How to create a broadband HR coating HR 650-1120 nm /0° out of three single HR systems. 15 Thin film basics
HR standards
R+T = 1 - losses 100
Practically the reflection for coa - tings with low losses through T,R % R absorption and scattering is 70 R = 1-T. 60 For 1064 nm /0° a standard EBE- coating has absorption <20 ppm 50 and scattering <150 ppm. Lower 40 T losses (<10 ppm) can be achie - 30 ved with IBS coatings (page 75). 20 For mirrors it is easier to measu - re the transmission than reflec- 10 tion with standard spec tro pho to- 0 900 950 10001050 1100 1150 1200 1300 meters. For this reason we nm normally provide transmission Transmission and reflection of a standard HR 1064 nm /0°. curves for mirrors.
HR – bandwidth 100
Different coating material com- T % binations have different band- 80 widths. Not every combination 70 is suitable for every wavelength 60 or application. 50 40 30 4 3 2 1 type 20 10 0 350 400 450 500 nm 550
The transmission of four different types of coating material combinations.
Wavelength shift 100
with changing AOI T % 80 With increasing angle of inciden - 70 ce (AOI) the central wavelength of a dielectric coating shifts to 60 shorter wavelengths. 50 40 The example shows a standard 30 HR 1064 nm /0°. 45° 30° 15° 0° It shifts about 10% when using 20 AOI = 45° but only less than 1% 10 when using AOI < 13°. 0 800 850 900 950 10001050 1100 1150 1200 nm 1300
Wavelength shift with changing AOI of a standard HR 1064 nm /0° 16 back to Contents Coating guide
HR – polarization 100 s
Dielectric mirrors have a broa - R % der reflection band and higher 80 reflection for s-polarized light 70 u compared to p-polarized light. 60 50 The example shows a standard 40 HR 1064 nm /45° will achieve: p Rs > 99.9% 30 Ru > 99.8% 20 Rp > 99.7% 10 0 900 950 1000 1050 1100 1150 1200 nm 1300 Reflection of a standard HR 1064 nm /45° with different polarizations.
HR – phase 180
In the reflected phase a stan- P [°] dard mirror has a shift of 180°. 90 By a simple variation of the top layer thickness the phase b) falls down to zero. 0 The example shows the reflected phase of a mirror HR a) 1064 nm / 0° -90 a) standard design b) phase optimized
-180 If necessary every coating can 900 950 1000 1050 1100 1150 1200 nm 1300 be optimized for its phase specification. Reflected phase of different coating designs HR 1064 nm /0°
HR – GDD 180 (Group Delay Dispersion)
Standard mirrors have already 90 a low GDD but only at the cen- ter wavelength as shown here for standard mirror HR 1064 s 0 nm /45°. Phi'' [fs²] Especially for fs-laser systems p the GDD becomes important. -90 LASEROPTIK can supply GDD optimized optics to your speci- For more information see -180 fications. 900 950 10001050 1100 1150 1200 nm 1300 chapter “Dispersive coatings” starting on page 61. GDD of a standard mirror HR 1064 nm /45° 17 Thin film basics
LIDT 1 (Laser Induced Damage Threshold) L I D T type 0 The LIDT of a coating strongly type 1 depends on coating materials normed LIDT type 2 0.5 type 3 and production methods. type 4 Normally coatings with the highest LIDT will not have the highest reflection. 0 100 300 500 700 900 1100 nm 1300 The example shows LIDT (pulsed la ser) and reflection 100 for different mirror types HR (0°) made with different coat- ing materials (EBE). R % 99 Reflection The peaks in LIDT result from type 0 the water band at 940 nm. type 1 type 2 98 type 3 + 4
100 300 500 700 900 1100 nm 1300
LIDT and reflection shown for different mirror types HR (0°) made with different coating materials (EBE).
The LIDT also depends on 1.00 the repetition rate and pulse width. 0.75 Two rules of thumb exist for pulsed laser systems: 0.50 -lg (rep-rate) 1) LIDT ~ 2 0.25 ______2) LIDT ~ √pulse duration 0 1110100000 10000
Going down from ns-pulses LIDT normed to repetition rate 1 Hz repetition rate [Hz] to ps-pulses the square root rule will not fit anymore, the damage mechanisms change. 2.5
2.0
expected 1.5 square root law fs ps ns 1.0
0.5
For more information regarding 0 LIDT and its measurement see LIDT normed to pulse width 10 ns 10–6 10–3 100 page 114. pulse duration [ns] 18 back to Contents Coating guide
Tips and tricks
Sometimes it is possible to im- Use a small AOI. 100 prove the performance of a
laser system by changing the You can achieve the sharpest T % 0° setup, such as working in- edge for a filter coating and the 80 30° versely with the wavelengths broadest HR-range and highest 70 45° or changing the polarization reflection with an angle of inci- 60 (if possible). Here are some dence AOI = 0°. 55° 50 recommendations. The example shows four differ- ent short pass filters with the 40 sa me type of design, centered 30 at the same short edge but op- 20 timized for different AOIs. 10 0 900 950 1000 1050 1100 1150 nm 1250
Use the main wavelength 100 in reflection. T % Due to the natural variations in 80 refractive index and thickness 70 of each layer in a multi-layer 60 coating normally the toleran ces for the HR-range will be much 50 better than for HT-areas. So it is 40 easier to produce high reflec- 30 tion than high transmission. 20 The example shows the margin of error for a standard coating 10 HR 808 nm /0° made by EBE. 0 Note: A higher precision can be 500 600 700 800 900 1000 nm 1200 achieved by using IAD or sput- ter techniques.
Avoid high transmission 100 around /2. λ T % It can be critical to achieve high 80 transmission around half of the 70 center wavelength of a mirror 60 coating. Here a so cal led /2- peak can appear. The depthλ of 50 this peak varies from 0% to 40 100% depending on the thick- 30 ness ratio of the used coating materials (see diagram show- 20 ing 3 different ratios), angle of 10 incidence, wave length and con- 0 dition of the coating machine. 450 550 650 750 850 950 1050 nm 1250 With a speci al coating techni- que it is possible to minimize this peak. 19 Thin film basics
Better use a Long Pass than 100 a Short Pass Filter as ... T % – the coating will be thinner 80 (and hence probably cheaper). 70 – potentially you can use coa - 60 ting material with lower absorp- 50 tion and/or higher LIDT. – you will have no effects from 40 the /2-peak. 30 λ For example the SP (HT 355 nm 20 HR 808 nm /0°) will have some absorption at 355 nm, the LP 10 coated with a dif ferent material 0 300 400 500 600 700 800 nm 1000 will not.
Use HT/AR with p-pol and 100 HR with s-pol. T % High transmission can be easier 80 achieved with p- than with s- 70 polarized light and vice versa 60 for high reflection. Normally this p s rule also applies to AR coatings. 50 For example see the different 40 polarizations of the shown LP 30 (HR 532 nm/s HT 650-900 nm/p /45°). 20 10 0 450 500 600550650 700750 800 850 nm 950
Use a Polarizer with the Brewster angle.
The best extinction ratio for a 100 polarizer can be achieved by
using the Brewster angle. T % For example, on Fused Silica 80 (against air) choose AOI close to 70 55.4°. 60 The often requested Polarizer p 56° s working with AOI = 45° has a 50 45° smaller opera ting range and 40 thus lower tolerances, see illus- 30 tration right. Additionally you TFP 56° TFP 45° TFP 45° TFP 56° do not need an AR coating on 20 the rear surfa ce as by using the 10 Brewster angle the reflection of 0 an uncoated surface is zero, but 10001020 1040 10601080 1100 nm 1120 Rp ~0.6 % with AOI = 45° (at 1064 nm, on FS against air). 20 back to Contents Coating guide
Production methods Overview coating technologies
Evaporation
EBE Electron Beam Evaporation Columnar structure
Substrate
IAD Ion Assisted Deposition
IP High packing density, Ion Plating some defects/cavities
Substrate
Sputtering
MS Magnetron Sputtering }
IBS Highest packing density, Ion Beam Sputtering lowest losses
Substrate 21 Production methods
Comparison
You have to choose the coat- Coating technique preferences EBE lAD IP MS IBS ing technique (and the best Coating optical properties high reflection coating materials!), that fits best weighting the importance lowest losses of each criteria. low absorption By discussing your applica- low scattering tions and targets with LIDT pulsed LASEROPTIK we will be able to propose an optimal solution LIDT cw for your coating. GDD - chirped mirrors Ievel of difficulty Wavelength areas VUV UV VIS NIR IR Substrate properties different substrate materials temperature sensitive substrates length / height of substrates strongly curved substrates Coating properties uniformity low stress layer purity hardness Environmental properties space harsh environments temperature changes vigorous cleaning Efficiency/costs short coating process time (rate) low price size + quantity of substrates
= specifically suitable = can be used = normally unsuitable 22 back to Contents Coating guide
Substrate
150 -350 °C
ALD : Atomic Layer Deposition
Reaction chamber
Atomic Layer Deposition (ALD) is a special As there is no need to add energy (like using Chemical Vapour Deposition (CVD) technique an additional ion source) to achieve a better for innovative and custom-tailored optical density, chemical processes such as ALD typi- applications with extreme film conformality cally show low internal stress. and thickness control at the sub-nano level. Several different reaction chambers are avail- ALD bases on a sequential, self-limiting, layer- able to support substrate sizes from a few mil- by-layer deposition. A solid film is formed by limeters to 300 mm in all dimensions and can chemical reactions between the gas phase of easily be exchanged. Special prisms precursor molecules taking place on the sub- strate surface, which is typically preheated The most common coating materials (SiO2, (150-350 °C) to thermally initiate this reaction. Al2O3, TiO2, Ta2O5…) are available while pure metals or fluorides are still challenging and The film forms sequentially by only one mono- require some additional development and layer per cycle. This provides an extreme depo- optimization. sition conformality and thickness control but increases the coating time. The growth is natu- rally pinhole free and the packing density is close to the bulk material.
Another special feature of ALD is the possibili- ty to coat nearly any 3D-optic, even with a high aspect ratio or strongly curved surfaces, e.g. Pros and cons of ALD: prisms, hemispheres or tubes. All surfaces can be coated at once or can also be protected if + Coating on 3D-optics needed. + Extreme film conformality + Excellent microstructure + Low internal stress ± All surfaces coated – Low deposition rate 23 Production methods
Substrates
E-gune EBE : Electron Beam Evaporation
Electron Beam Evaporation (EBE) is the con - Pros and cons of EBE ven tional coating technique. Due to its high evaporation rate the coating time is relatively + High deposition rate short. In addition to the large capacity it has a + Good cost-performance ratio good cost-per formance ratio. + High LIDT + DUV to IR Coatings are done in a heated ( > 250 °C) high – Thermal drift vacuum chamber using electron beam guns. Each gun emits a high-voltage electron beam that is focused into a water cooled rotating cru- cible, containing the coating material. The beam melts and evaporates the material at temperatures of about 2000 °C.
Rather than generated with an electron gun Thermal Evaporation (TE) can also be achieved with an evaporation boat which is heated by a quarter-wave measurement on a witness sam- strong electrical current. ple, whereas the physical thickness is detect- ed with a crystal oscillator. Due to the high vacuum environment the mate- rial vapour moves as cloud to the substrates, Oxide materials are reactively deposited in an mounted in a spherical or plano calotte in the oxygen atmosphere of some 10-4 mbar in or- top of the chamber. der to compensate the decomposition during evaporation. The vapour condenses on the surface of the substrate forming a film with mainly columnar Many different coating materials (metals, me - structure. To match surface geometries and to tal-oxides or fluorides and sulfides) can be achieve an optimal coating thickness distribu- used, so the application range is from DUV to tion the calotte is being rotated. Optical thick- IR. Due to the porous columnar structure EBE ness control is ensu red by monochromatic coatings show some thermal drift. 24 back to Contents Coating guide
Substrates
E-GunE-gun O2 +160 V Ar RF IAD : Ion Assisted Deposition
Ion Assisted Deposition (IAD) is based on a Pros and cons of IAD coating system as described before for Elec- tron Beam Evaporation (EBE) but with an addi- + Density near to bulk tional plasma source. The plasma is directed + No thermal drift onto the calotte and provides a bombardment + High deposition rate of the growing layer which results in a denser + Internal stress can be optimized micro structure and therefore eliminates the ± VIS / NIR: LIDT close to e-beam thermal drift.
The plasma is generated by a DC-discharge with a RF-heated cathode. Caused by the strong discharge of about 40 amps, the mole- cules in the vapour are activated and ionized. The reactive argon and oxygen ions hit the substrate with energies up to 150 eV.
IAD still uses the high evaporation rate of EBE what helps to keep the costs down, but it is limited to certain coating materials, for exam- ple fluorides cannot be used. By using opti- mized parameters the internal stress can be minimized. In the VIS/NIR normally the LIDT is close to e-beam. 25 Production methods
Substrates
E-gune-Gun IP : Ion Plating
Ion Plating (IP) uses ions to produce dense Pros and cons of IP layers, but in a different way than IAD. + Extremely mechanically resistant LASEROPTIK works with Reactive Low Voltage + High density, high refractive index Ion Plating (RLVIP) which results in extremely + High deposition rate mechanically resistant coatings. – High stress
A low voltage electrical arc is ignited from a plasma source directly into the crucible, so the coating material is well ionized. This and the different potentials of the crucible and the calotte lead to high kinetic energy of the parti- cles hitting the substrates. So the growing lay- er gets a density close to 100%. With this method very high refractive indices can be achieved.
The process gas is argon, for metal-oxides we use additional oxygen as reactive gas.
The coatings are extremely hard and do not react on changes in temperature or humidity but they have a high level of stress.
Plasma above IP crucible 26 back to Contents Coating guide
Substrates
Magnets Ar + O2 Targets
MS : Magnetron Sputtering
Magnetron Sputtering (MS) uses a magnetron coa tings and cw-applications very high LIDT plasma for sputtering a metal layer on the can be achieved. substrates and oxidizing it to a stoichiometric me tal-oxide in a microwave plasma after- As the process works with low temperatures wards. This technique allows to produce very coatings on plastic or other non-glasslike ma- dense and hard coatings. terials (e.g. fiber ends) are possible.
In the coating machine a drum with a diameter Like all sputter techniques, coatings made by of 120 cm holds the substrates. It rotates verti- MS may have high stress, depending on the cally in front of the two magnetrons and micro - wavelength region and coating materials used. waves. Pros and cons of MS A plasma of ionized argon forms in front of the target. The positively charged argon ions are + Very dense and hard coatings accelerated toward the negatively charged + Space certified by ESA target, where they strike the face of the target + High precision and sputter metal atoms on the substrates. + High LIDT for UV-coatings and cw + Low temperature coatings Rotating into the microwave plasma the metal – Compressive stress (case dependent) film is oxidized and ready for the next cycle. The coatings are very hard and mechanically resistant and can work in nearly every environ- ment. Specific coatings are space certified by ESA (see page 76).
Two different material targets can be used in one configuration. The sputter rates are very stable, so the thickness control is done with high precision simply by time and with an optical monitor as backup. Especially for UV- 27 Production methods
Substrates
RF IBS : Ion Beam Sputtering Ar 1,5 kV
Ion Beam Sputtering (IBS) is the most advan - The stress can be reduced by compensating ced deposition technology for the most critical layers deposited on the rear surface including O2 Targets demands on laser optics. additional optical properties, e.g. working as an AR coating. IBS works with RF-guns, typically used for satel- lite propulsion. Argon ions are accelerated by At LASEROPTIK we actually have 10 machines approx. 1.5 kV onto a metal target. Coating ma- for special requirements in operation, e.g. high terial is sputtered off the target and condenses power supermirrors with superior reflectivity on a ver tically rotating substrate fixture. (99.99x %) and lowest losses (<10 ppm), com- A uniform coa ting distribution is limited to an plex filter designs or coatings on crystals. area of about 30 cm in dia meter for the stan- dard IBS machines. With our GDD measurement setup we also offer dispersive coatings (see page 61). Our IBS coating plants have been designed with a secondary RF plasma source. It emits oxygen ions directly onto the substrate surfa - Pros and cons of IBS ces in order to receive well-oxidized, non- ab sorbing oxide layers. + Highest precision + Lowest losses With the accuracy of LASEROPTIK’s broadband + Excellent micostructure monitoring systems, fractional parts of a mono - + High density layer can be detected. As a result of highest ± Stress, can be compensated precision in film growth and an amorphous, al- – Low deposition rate most defect free microstructure IBS is conside - red as the most advanced coating technology in today’s thin film industry.
As magnetron sputtering, IBS is a “cold“ pro - cess in which the internal temperature does not exceed 100°C. 28 back to Contents 29
Coatings
Standard coatings for the most common laser types, sorted by wavelength areas Variables, metal and OPO coatings Dispersive coatings Coatings on special substrates Coatings for special applications or environmental conditions
Every coating type can be optimized for every • substrate material • wavelength • reflection / transmission value • angle of incidence • polarization • GDD value • ... or, alternatively we can create a totally new design for you.
If not mentioned otherwise all values and diagrams are given • for the standard substrate material used in the described wavelength area (mostly Fused Silica or CaF2). • without consideration of the rear sur- face • with EBE coating technique for a good cost-performance ratio. 30 back to Contents Coatings
VUV / Excimer 120-179 nm
Coating types
VAR VAR [nm] AR (0°); R < method AR (45°); R < method λ DAR 157 0.5% on Fluoride EBE 0.75% on Fluoride EBE TAR 172 0.5% on Fluoride EBE 0.75% on Fluoride EBE AR BBAR MAR WAR
HR HR [nm] HR (0°); R > method HR (45°); R > method λ DHR 126 84% on Fluoride EBE 75% on Fluoride EBE BBHR 130 85% on Fluoride EBE 80% on Fluoride EBE HR MHR 149 91% on Fluoride EBE 89% on Fluoride EBE WHR 157 94% (goal 97%) on Fluoride EBE 93% (goal 95%) on Fluoride EBE Metal 172 95% on Fluoride EBE 94% on Fluoride EBE
PR DPR TFP [nm] AOI method λ BBPR 157 Rp<0.3%, Rs>87% 72° on CaF2 EBE VA PR GOC
LP SP VA [nm] 0°–> 45°; T = method λ NF 157 75% –> 2% on CaF2 EBE MP 10% –> 70% on CaF2 EBE Filter BP REF
LASEROPTIK has longtime experience with coatings in the Vacuum Ultraviolet (VUV) range TFP (120-179 nm), especially for 157 nm including dedicated metrology (see page 113). CP BBPOL The main reason for losses in this spectrum is absorption of water and hydrocarbons. VUV-CaF2 Polarizer substrates are used to counter these losses. A surface roughness of RMS < 0.3 nm helps to de- crease the losses for all coatings.
We guarantee LIDT > 400 mJ/cm2 with 15 ns pul ses for HR 157 nm /0°.
Our mirrors withstand 2.5 billion pulses at 10 mJ/cm2 without any detectable degradation as VA reported from a longterm test. The values for PR and AR coatings will be in the same range. GOC GP Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 31 VUV/Excimer 120-179 nm 126 | 130 | 149 | 157 | 172 nm
Ar2 - F2
Examples
10 100 R % R % 8 80 7 70 6 60 5 50 4 40 3 30 2 20 1 10 0 0 140 145 150 155 160 165 170 nm 180 140 145 150 155 160 165 170 nm 180
AR 157 nm / 0° [B-00768] HR 157 nm / 0° [B-00649] 157 nm: R < 0.5% 157 nm: R > 94% (goal R > 97%)
100 100 R % R % 80 80 s 70 70 60 60 50 50 40 40 30 30 20 20 p 10 10 0 0 140 145 150 155 160 165 170 nm 180 140 145 150 155 160 165 170 nm 180
R 50% 157 nm / 45° [B-06013] TFP 157 nm / 72° [B-01280] 157 nm: R ± 5% 157 nm: Rp < 0.3%, Rs > 87%
100 100 including B-00768: AR157 nm/0° on rear surface R % T % 80 80 70 70 60 0° 60 15° 50 50 25° 40 40 35° 30 30 20 45° 20 10 10 0 0 140 145 150 155 160 165 170 nm 180 120 130 150140160 170180 190 200 nm 220
VA 157 nm / 0-45° T 75-1% [B-11719] Al + Protection Layer - VUV [B-02250-01] 157 nm: 0°: T > 70% (goal T > 75%); 45°: T < 2% (goal T < 1%) 120-220 nm /0°: R > 65%
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UV / Excimer 180-379 nm
Coating types
VAR VAR [nm] AR (0°); R < method AR (45°); R < method λ DAR 193 0.5% EBE 0.75% EBE TAR 248 0.25% EBE 0.75% EBE AR BBAR 266 0.25% EBE 0.6% EBE MAR 355 0.2% EBE 0.6% EBE WAR 0.05-0.1%* low loss IBS 0.1-0.6%* low loss IBS * depending on price, substrate size and laser power
HR DHR HR [nm] HR (0°); R > method HR (45°); R > method λ BBHR 193 96% EBE 92% (goal 96%) EBE HR MHR 96% (goal 98%) on Fluoride EBE 95% on Fluoride EBE WHR 213 98% EBE 97% EBE Metal 248 99.5% EBE 99% EBE 266 99.5% EBE 99.5% standard EBE 99.5% IBS 99.5% high power MS PR 308 99.5% EBE 99.2% EBE DPR 99.7% IBS 99.7% IBS BBPR 343 99.5% EBE 99.2% EBE VA 351 99.5% EBE 99.2% EBE PR GOC 355 99.5% high power MS 99.5% standard EBE 99.9% low loss IBS 99.9% low loss IBS 99.5% high power MS LP SP NF MP TFP [nm] AOI method Filter λ BP 193 Tp>80%, Ts<10% 73° EBE REF 248 Tp>80%, Ts<2% Brewster EBE 266 Tp>90%, Ts<2% Brewster EBE 355 Tp>94%, Ts<2% Brewster EBE TFP Tp>96%, Ts<0.2% Brewster IBS CP BBPOL Polarizer VA [nm] 0°–> 45°; T = method 193λ 80% -> 10% EBE 248 90% -> 2% standard EBE 95% -> 1% high power MS 266 92% -> 1% standard EBE VA 355 92% -> 1% standard EBE GOC 92% -> 1% non-shifting IAD GP Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 33 UV/Excimer 180-379 nm 193 | 213 | 248 | 266 | 308 | 325 | 337 | 343 | 351 | 355 | 375 nm
ArF - KrF - XeCl - HeCd - N2 - XeF - Alexandrite 3rd, 4th, 5th of Nd:YAG/YVO4 - Yb:YAG
Examples
10 100 R % R % 8 80 7 70 R 90-100% 6 60 5 50 4 40 3 30 2 20 1 10 0 0 180 190 200210 220 230240 250 260 nm 280 200300 400 500 600 nm 700
AR 193 nm + 248 nm / 0° [B-00790] HR 248 nm + 633 nm / 45° [B-03680] 193 nm: R < 0.5%; 248 nm: R < 0.5% 248 nm: R > 99%; 635 nm: R > 98%
100 100 T % R % 80 80 70 s 70 p x 10 p s x 10 s 60 60 u 50 50 40 p 40 30 30 20 20 10 10 0 0 260 270280290 300310 320 320 320 nm 360 335 340 345 350 355 360 365 nm 375
R 50% 308 nm / 45° [B-01937] TFP 355 nm / 55.9° [B-11227] 308 nm: R ± 3% 355 nm: Tp > 96%, Ts < 0.2% (IBS-coating)
100 100 T % 0° R % 80 80 15° 70 70 25° 45° 0° 60 60 35° 50 50 45° 40 40 30 30 20 20 10 10 0 0 220 230240 250 260270 nm 290 220 240 260280 300 320 340 360 380 nm 420
VA 248 nm / 0-45° [B-07573] HR 250-350 nm / 0-45° [B-07720] 248 nm: 0° -> 45°; T = 95% -> 1% (MS-coating) 250-350 nm: Ravg > 98.5%
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VIS 380-779 nm
Coating types
VAR VAR [nm] AR (0°); R < method AR (45°); R < method λ DAR 532 0.2% EBE 0.6% EBE TAR 0.05-0.1%* low loss IBS 0.1-0.6%* low loss IBS AR BBAR 633 0.2% EBE 0.6% EBE MAR * depending on price, substrate size and laser power WAR
HR [nm] HR (0°); R > method HR (45°); R > method λ HR 405 99.8% EBE 99.7% EBE DHR 488 99.85% EBE 99.8% EBE BBHR 514 99.85% EBE 99.8% EBE HR MHR 515 99.8% high power EBE 99.8% high power EBE WHR 99.9xxx%* low loss IBS 99.9xxx%* low loss IBS Metal 532 99.8% high power EBE 99.8% high power EBE 99.9xxx%* low loss IBS 99.9xxx%* low loss IBS 550 99.85% EBE 99.8% EBE PR 578 99.85% EBE 99.8% EBE DPR 633 99.85% EBE 99.8% EBE BBPR 99.9xxx%* low loss IBS 99.9xxx%* low loss IBS VA 694 99.85% EBE 99.8% EBE PR GOC 760 99.85% EBE 99.8% EBE * 99.9xxx% means that we can optimize the reflection/ transmission to your needs. The coating price results from the chosen grade of reflection/difficulty, see estimated multiplier: LP Price x 1 x 2 x 3 SP EBE IBS lowest loss NF R > 50% R > 99.85% MP Filter R > 99.9% BP R > 99.95% REF R > 99.999%
TFP [nm] AOI method λ TFP 515 Tp>90%, Ts<3% 45° EBE CP Tp>99%, Ts<0.1% Brewster IBS BBPOL 532 Tp>90%, Ts<2% 45° IAD Polarizer Tp>96%, Ts<1% Brewster IAD Tp>99%, Ts<0.1% Brewster IBS
VA [nm] 0°–> 45°; T = method 532λ 92% -> 1% standard EBE VA 92% -> 1% non-shifting IAD GOC GP Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 35 VIS 380-779 nm 405 | 450 | 476 | 488 | 514 | 515 | 532 | 550 | 578 | 633 | 656 | 671 | 694 | 760 nm Diode laser - Tm:YLF - Kr+ - Ar+ - Er:KYW - Copper vapour - HeNe - Ruby - Alexandrite 2nd of Nd:YAG/YVO4/YLF - Yb:YAG
Examples
10 100 T % R % 8 80 7 70 p 6 0° 60 50 5 u 4 40 45° 3 30 s 2 20 1 10 0 0 500 550 600 650 700 750 nm 800 450 470 490 510530 550 570590 610 nm 650 AR 633 nm / 0-45° [B-11397] HR 532 nm / 45° [B-00458] 633 nm: R < 1% 532 nm: Ru > 99.8%
100 100 T % T % 80 80 p 70 70 60 60 u p x 10 p s x 10 s 50 50 40 40 s 30 30 20 20 10 10 0 0 450 500 550 600 650 700 nm 750 500 510 520 530 540 550 nm 560
R 50% 532-633 nm / 45° [B-00688] TFP 532 nm / 55.4° [B-11321] 532-633 nm: Ru ± 5% vs. theoretical curve 532 nm: Tp > 99%, Ts < 0.1% (IBS-coating)
100 100 0° x 10
T % 15° T % 80 80 25° 70 70 35° 60 60 45° 50 50 40 40 30 30 20 20 10 10 0 0 450 470 490510 530 550570 590 610 nm 650 350 400450 500 550600 650 700 nm 800
VA 532 nm / 0-45° T 92-1% [B-01194] HR 400-700 nm / 0° [B-01845] 532 nm: 0° -> 45°; T = 92% -> 1% 400-700 nm: Ravg > 99%
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NIR 780-1029 nm
Coating types
VAR VAR [nm] AR (0°); R < method AR (45°); R < method λ DAR 780 0.2% EBE 0.6% EBE TAR 800 0.2% EBE 0.6% EBE AR BBAR 0.05-0.1%* low loss IBS 0.1-0.6%* low loss IBS MAR 808 0.2% EBE 0.6% EBE WAR 940 0.2% EBE 0.6% EBE 0.05-0.1%* low loss IBS 0.1-0.6%* low loss IBS * depending on price, substrate size and laser power HR DHR BBHR HR [nm] HR (0°); R > method HR (45°); R > method λ HR MHR 780 99.85% EBE 99.8% EBE WHR 800 99.9xxx%* low loss IBS 99.9xxx%* low loss IBS Metal 808 99.85% EBE 99.8% EBE 850 99.85% EBE 99.8% EBE 914 99.85% EBE 99.8% EBE PR 940 99.8% standard EBE 99.75% standard EBE DPR 99.85% non-shifting IAD 99.8% non-shifting IAD BBPR 99.9xxx%* low loss IBS 99.9xxx%* low loss IBS VA 976 99.85% EBE 99.8% EBE PR GOC 980 99.85% EBE 99.8% EBE * 99.9xxx% means that we can optimize the reflection/ transmission to your needs. The coating price results from the chosen grade of reflection/difficulty, see estimated multiplier: LP Price x 1 x 2 x 3 SP EBE IBS lowest loss NF R > 50% R > 99.85% MP Filter R > 99.9% BP R > 99.95% REF R > 99.999%
TFP TFP [nm] AOI method λ CP 800 Tp>99% , Ts<0.1% Brewster IBS BBPOL 808 Tp>95% , Ts<1% Brewster EBE Polarizer 940 Tp>95% , Ts<1% Brewster IAD
VA [nm] 0° –> 45°; T = method 8λ08 95% -> 1% non-shifting IAD VA 940 95% -> 1% non-shifting IAD GOC GP Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 37 NIR 780-1029 nm 780 | 800 | 808 | 850 | 914 | 940 | 946 | 976 | 980 nm Diode laser - Ti:Sapphire - Er:YLF/YAP - InGaAs diode weak Nd:YAG/YVO4
Examples
10 100
T % R % 8 80 7 70 6 60 x 10 5 50 4 40 3 30 2 20 1 10 0 0 700 800 9001000 1100 1200 nm 600 650700750 800850 900 nm 1000
AR 785-1030 nm /0° [B-07312] HR 800 nm /0° single stack [B-06166] 785-1030 nm: R < 0.5% 800 nm: R > 99.8% single stack (quarter wave layers)
100 100 p x 10 s x 10
T % T % 80 80 70 70 p 60 60 50 50 40 40 s 30 30 20 20 10 10 0 0 778 778.5 779 779.5 780 780.5 781 nm 782 860 880900 920 940 960 980 nm 1020
IF 780 nm / 6° [B-06650] TFP 940 nm / 56° [B-10213-01] 780 nm: FWHM 0.37 nm, best effort, angle tuning (IBS-coating) 940 nm: Tp > 95%, Ts < 1% (IAD-coating)
100 100
T % T % 15° 0° 80 80 70 70 25° 60 60 35° 50 50 45° 40 40 30 30 20 20 10 10 0 0 700 750 800 850 900 950 nm 1000 900 910 920930 940 950960 970 980 nm 1000
VA 808 nm / 0-45° T 95-1% [B-01476-01] HR 905-945 nm HT 975-985 nm / 45° p [B-05178] 808 nm: 0° -> 45°; T= 95% -> 1% (IAD-coating) 905-945 nm: Rp > 95%; 975-985 nm: Rp < 4% (IBS-coating)
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NIR 1030-1064 nm
Coating types
VAR VAR [nm] AR (0°); R < method AR (45°); R < method λ DAR 1064 0.1% EBE 0.6% EBE TAR 0.05-0.1%* low loss IBS 0.1-0.6%* low loss IBS AR BBAR * depending on price, substrate size and laser power MAR WAR HR [nm] HR (0°); R > method HR (45°); R > method 1030λ 99.7% high power EBE 99.5% high power EBE HR 99.85% standard EBE 99.8% standard EBE DHR 99.9xxx%* low loss IBS 99.9xxx%* low loss IBS BBHR 1053 99.85% EBE 99.8% EBE HR MHR 1064 99.7% high power EBE 99.5% high power EBE WHR 99.9% standard EBE 99.8% standard EBE Metal 99.9xxx%* low loss IBS 99.9xxx%* low loss IBS * 99.9xxx% means that we can optimize the reflection/ transmission to your needs. The coating price results from the chosen grade of reflection/difficulty, see estimated multiplier: PR Price x 1 x 2 x 3 DPR EBE IBS lowest loss BBPR R > 50% R > 99.85% VA PR R > 99.9% GOC R > 99.95% R > 99.999%
LP TFP [nm] AOI method λ SP 1064 Tp>95%, Ts<5% 45° cube EBE NF Tp>99%, Ts<1% 45° IBS MP Tp>95%, Ts<2% Brewster EBE Filter BP Tp>99%, Ts<0.1% Brewster IBS REF
VA [nm] 0°–> 45°; T = method λ TFP 1064 95% -> 1% EBE CP 95% -> 1% non-shifting IAD BBPOL Polarizer LIDT for HR 1064 nm /0° with different methods
method LIDT - pulsed (10 ns, 1 Hz) LIDT - cw (depending on cooling) energy per effective beam area power per effective beam diameter EBE, high power > 80 J / cm² > 10 kW / cm VA EBE, standard > 40 J / cm² > 10 kW / cm GOC IBS > 40 J / cm² > 100 kW / cm.. GP Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 39 NIR 1030-1064 nm 1030 | 1040 | 1047 | 1053 | 1054 | 1064 nm Fibre laser - Yb:YAB/YAG - Nd:glass Nd:YAG/YVO4/YLF
Examples
10 100
T % R % 8 80 7 70 6 60 5 50 4 40 s 3 30 55° 2 p 20 45° 35° 1 10 0 0 900 94098010201060 11001140 1180 1220 nm 1300 500 580660740 820900 980 1060 1140 nm 1300
AR 1064 nm / 45° low polarizing [B-07674] R > 80% 633 nm HR 1064 nm / 45 ± 10° Type 3 [B-06544] 1064 nm: Ru < 0.6%; IRs-RpI < 0.4% 633 nm: R > 80%; 1064 nm: Ravg > 99.7%
100 100
T % left T % 80 80 70 70 middle p x 10 p s x 10 s 60 60 50 50 right 40 40 30 30 20 20 10 10 0 0 102010401060 1080 1100 nm 1120 10001020 1040 1060 1080 1100 nm 1120
GOC 1064 nm / 0° [B-05981] TFP 1064 nm / 55.4° [B-11324] 1064 nm: T 25-75% min. variation on substrate (IAD-coating). 1064 nm: Tp > 99%, Ts < 0.1% (IBS-coating) More details about Gradient Output Coupler GOC on page 50.
100 100
0° T % T % 80 15° 80 25° 70 70 35° x 10 60 60 45° 50 50 40 40 30 30 20 20 10 10 0 0 900 9409801020 10601100 1140 1180 1220 nm 1300 1010102010301040 10501060 1070 1080 nm 1100
VA 1064 nm / 0-45° T 95-1% [B-00431-01] HT 1030 nm HR 1064 nm /0° [B-06240] 1064 nm: 0° -> 45°; T= 95% -> 1% 1030 nm: R < 1.3%; 1064 nm: R > 99.4% (IBS-coating)
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NIR 1030-1064 nm Combinations of harmonics
Coating types
VAR 5th harmonic 4th harmonic 3rd harmonic 2nd harmonic DAR DAR 213 nm 266 nm 355 nm 532 nm 1064 nm AOI method TAR R < 1% R < 0.8% 0° EBE AR BBAR R < 1% R < 0.5% 0° EBE MAR R < 1% R < 0.5% 0° EBE WAR R < 0.75% R < 0.5% 0° EBE R < 0.5% R < 0.3% 0° EBE R < 0.2% R < 0.1% 0° IBS HR R < 1% R < 0.75% 45° EBE DHR TAR BBHR R < 1% R < 1% R < 0.5% 0° EBE HR MHR R < 1% R < 1% R < 0.5% 0° EBE WHR R < 0.3% R < 0.3% R < 0.3% 0° IBS Metal DHR R > 99% R > 99.5% 0° EBE R > 99% R > 99.5% 45° EBE PR R > 99% R > 99.5% 45° EBE DPR R > 99.8% R > 99.8% 0° EBE BBPR R > 99.9xx% R > 99.9xx% 0° IBS VA MHR PR GOC R > 98.5% R > 99% R > 99.5% 45° EBE R > 99% R > 99% R > 99% 0° EBE R > 97% R > 98% R > 99% R > 99.5% 45° EBE LP LP SP Rs > 99% Rp < 5% Rp < 3% Rp < 3% Rp < 3% 45° EBE NF R > 99.5% R < 6% R < 6% 45° EBE MP R > 99.5% R < 3% R < 2% 45° MS Filter BP Rs > 99.5% Rp < 1% Rs < 1% 45° IBS REF R > 99.8% R < 2% 0° EBE Rs > 99.8% Rp < 1% 45° EBE SP TFP R < 5% R > 99.5% 0° EBE CP R < 10% R > 99.8% 0° EBE BBPOL R < 2.5% R < 2% R > 99.9xx% 0° IBS Polarizer R < 5% R > 99.85% 0° EBE Rp < 3% Rs > 99.5% 45° EBE NF R < 8% R > 99.5% R < 8% R < 8% 45° MS R < 5% R > 99.7% R < 5% 0° EBE Rp < 5% Rs > 99.7% Rp < 5% 45° EBE VA MP GOC Rp > 98% Rp > 98% Rs < 5% Rp < 5% 45° EBE GP R > 99% R > 99.5% R < 5% 45° EBE Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 41 NIR 1030-1064 nm 213 | 266 | 355 | 532 | 1064 nm as examples harmonics Nd:YAG/YVO4 can be adapted to all other wavelenghts
Examples
100 100
T % R % 80 80 70 70 60 60 x 10 x10 50 50 40 40 30 30 20 20 10 10 0 0 300 400 500 600700 800 900 1000 1100 nm 1300 300 400 500600 700 800 9001000 1100 nm 1300
AR 355 nm + 532 nm + 1064 nm /0° [B-00536] HR 355 nm + 532 nm + 1064 nm /0° Type 2 [B-04212] 355 nm + 532 nm: R < 1%; 1064 nm: R < 0.5% 355 nm + 532 nm + 1064 nm: R > 99%
100 100
T % T % 80 80
70 70 60 60 x10 50 50 40 40 30 30 20 20 10 10 0 0 300 350 400 450 500 550 nm 600 400 500600700 800900 1000 1100 nm 1300
R 50% 355 nm + 532 nm /45° [B-01788] HT 532 nm HR 1064 nm /0° [B-00001] 355 nm + 532 nm: R ± 5% vs theoretical curve 532 nm: R < 5%; 1064 nm: R > 99.85%
100 100
T % T % 80 80 70 70 60 60 x10 50 50 p s 40 40 30 30 20 20 10 10 0 0 400 500 600700 800 9001000 1100 nm 1300 300 400 500600 700 800 900 1000 1100 nm 1300
HR 532 nm R 50% 1064 nm /0° [B-11735] HT 355 nm/p HR 532 nm/s HT 1064 nm/p/45° [B-02977] 532 nm: R > 99.8%; 1064 nm: R ± 5% vs theoretical curve 355 nm: Rp < 5%; 532 nm: Rs > 99.7%; 1064 nm: Rp < 5%
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NIR 1065-2500 nm
Coating types
VAR VAR [nm] AR (0°); R < method AR (45°); R < method λ DAR 1342 0.2% EBE 0.6% EBE TAR 1550 0.2% EBE 0.6% EBE AR BBAR 0.05-0.1%* low loss IBS 0.1-0.6%* low loss IBS MAR 2100 0.25% non-shifting IAD 0.75% non-shifting IAD WAR 2300 0.25% EBE 0.75% EBE * depending on price, substrate size and laser power
HR DHR HR [nm] HR (0°); R > method HR (45°); R > method λ BBHR 1342 99.85% EBE 99.8% EBE HR MHR 99.9xxx%* low loss IBS 99.9xxx%* low loss IBS WHR 1535 99.85% EBE 99.8% EBE Metal 1540 99.85% EBE 99.8% EBE 1550 99.85% EBE 99.8% EBE 99.9xxx%* low loss IBS 99.9xxx%* low loss IBS PR 1573 99.85% EBE 99.8% EBE DPR 2010 99.8% EBE 99.7% EBE BBPR 2090 99.8% EBE 99.7% EBE VA 2100 99.8% standard EBE 99.7% standard EBE PR GOC 99.8% non-shifting IAD 99.7% non-shifting IAD 2300 99.8% EBE 99.7% EBE * 99.9xxx% means that we can optimize the reflection/ transmission to your needs. LP The coating price results from the chosen grade of reflection/difficulty, see estimated multiplier: Price x 1 x 2 x 3 SP NF EBE IBS lowest loss R > 50% MP Filter R > 99.85% BP R > 99.9% REF R > 99.95% R > 99.999%
TFP TFP [nm] AOI method λ CP 1342 Tp>90%, T<1% 45° IAD BBPOL Tp>96%, Ts<1% Brewster IAD Polarizer 1550 Tp>98%, Ts<1% 45° IBS 2100 Tp>95%, Ts<0.5% Brewster IAD
VA [nm] 0°–> 45°; T = method 1550λ 95% –> 1% EBE VA GOC GP Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 43 NIR 1065-2500 nm 1123 | 1320 | 1342 | 1535 | 1540 | 1550 | 1573 | 2010 | 2090 | 2100 | 2300 nm Yb, Er:KGW / KYW / glass - Er:YAG - Q-switched Nd:YVO4 - Tm, Ho:YAG - YSGG - Tm:YLF weak Nd:YAG/YVO4
Examples
100 100
R % T % 80 80 70 70 60 60 x 10 x 10 50 50 40 40 30 30 20 20 10 10 0 0 400 600 800 1000 1200 1400 1600 nm 600 700800900 10001100 1200 1300 1400 nm 1600
AR 457 nm + 914 nm + 1064 nm + 1320 nm /0° [B-03652] HT 671 nm HR 1342 nm /0° [B-03578] 457 nm + 914 nm: R < 1%; 1064 nm: R < 0.8%; 1320 nm: R < 1% 671 nm: R < 10%; 1342 nm: R > 99.85%
100 100
T % T % 80 80 70 70 60 60 p x 10 p s x 10 s 50 50 40 40 30 30 20 20 10 10 0 0 400 600 800 1000 1200 1400 1600 1800 nm 1260 1280 13001320 1340 1360 1380 nm 1420
BP 1050-1080 nm/0° on RG 850 incl. AR on rear side [B-05358] TFP 1342 nm /56° [B-07759] 400-1040 nm: Tavg < 2%; 1050-1080 nm: Tavg > 80% 1342 nm: Tp > 96%, Ts < 1% (IAD-coating) 1090-1900 nm: Tavg < 3% (IBS-coating)
100 100
T % 0° T % 80 80 15° 70 70 25° 60 60 35° p s 50 50 45° 40 40 30 30 20 20 10 10 0 0 1400145015001550 16001650 1700 1750 nm 1850 1000 1200 14001600 1800 2000 2200 nm 2600
VA 1550 nm /0-45° T 95 - 1% [B-12535] HR 1220-1560 nm /s HT 1620-2500 nm /p /45° [B-02997] 1550 nm: 0° -> 45°; T = 95% -> 1% 1220-1560 nm: Rs > 99%; 1620-2500 nm: Rp < 10%
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MIR > 2500 nm
Coating types
VAR VAR [nm] AR (0°); R < method AR (45°); R < method λ DAR 2940 0.25% on CaF2 EBE 1% on CaF2 EBE TAR 0.05-0.1% * on Sapphire IBS 0.1%-0.6% * on Sapphire IBS AR BBAR 3300 0.3% on CaF2 EBE 1% on CaF2 EBE MAR 4000 0.5% on CaF2 EBE 1% on CaF2 EBE WAR * depending on price, substrate size and laser power
HR HR [nm] HR (0°); R > method HR (45°); R > method λ DHR 2810 99.8% on CaF2 EBE 99.7% on CaF2 EBE BBHR 2940 99.7% on CaF2 EBE 99.7% on CaF2 EBE HR MHR 99.9xx%* on YAG IBS 99.9xx%* on YAG IBS WHR 3300 99.7% on CaF2 EBE 99.7% on CaF2 EBE Metal 4000 99.5% on CaF2 EBE 99.5% on CaF2 EBE * 99.9xx% means that we can optimize the reflection/ transmission to your needs.
PR DPR TFP [nm] AOI method λ BBPR 4000 Tp > 95%, Ts< 2% Brewster EBE VA PR GOC
LP VA [nm] 0°–> 45°; T = method λ SP 2940 90% -> 1% on CaF2 EBE NF MP Filter BP REF
LASEROPTIK has a dedicated EBE coating machine for infrared coatings made with non-radioacti - TFP ve ma te rials. Due to national environmental regulations we do not use ThF4, but still cover a ran - CP ge of up to = 4 µm for reflecting systems and up to = 10.6 µm for anti -reflecting systems. BBPOL λ λ Polarizer Coatings are applied on various IR substrates such as Ge, ZnSe, Sapphire, CaF2 and others. Metal coatings are also available for IR applications (see page 54).
VA GOC GP Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 45 MIR > 2500 nm 2810 | 2940 | 3300 | 4000 nm Er:YLF/YAG - OPO
Examples
10 100
T % R % 8 80 7 70 6 60 x 10 5 50 4 40 3 30 2 20 1 10 0 0 3400 3600 38004000 4200 4400 4600 nm 5000 2200 2400 260028003000 3200 3400 3600 nm 4000
AR 4000 nm /0° on CaF2 [B-02246] HR 2940 nm /45° [B-06023] 4000 nm: R < 0.5% 2940 nm: R > 99.7%
100 100
T % T % 80 80 70 70 p 60 60 u p x 10 p s x 10 s 50 50 s 40 40 30 30 20 20 10 10 0 0 2200 240026002800 30003200 3400 3600 nm 4000 3700 3800 3900 4000 4100 4200 nm4300
R 50% 2700-3300 nm / 45° [B-04184] TFP 4000 nm /55° on CaF2 [B-02823] 2700-3300 nm: Ru ± 5% vs theoretical curve 4000 nm: Tp > 95%, Ts < 2%
100 100
T % 0° R % 80 80 15° 70 70 25° 60 60 35° R 90-100% 50 50 45° 40 40 30 30 20 20 10 10 0 0 2700 2800 29003000 31003200 3300 3400 nm 3600 5001000 15002000 25003000 3500 4000 nm 5000
VA 2940 nm / 0-45° T 90-1% on CaF2 [B-03940] Au + Protection Layer [B-06039] 2940 nm: 0° -> 45°; T = 90% -> 1% IR: R > 97%
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Polarizer Thin Film / Cube / Broadband
Coating types
VAR Thin Film Polarizer TFP are cemented or optically contacted after DAR Normally is coated on a plate (that does not coating, some with an air gap. The output sur- TAR need to have any birefringence) and uses the faces need an AR at 0°. AR BBAR strong reflection difference between p- and s- MAR polarized light. Working with the Brewster an- Broadband Polarizer BBPOL WAR gle a high extinction ratio can be achieved and Separates the s- and p-polarized light in a no AR on the rear surface is required (see “tips broader range compared to the standard TFP and tricks”, page 19). but normally with a lower extinction ratio. HR It can be made by using a plate coated on DHR Cube Polarizer CP both sides and a large angle of incidence BBHR Is built out of two 45° prisms with a polarizing (AOI~72°) or a cube (special glass material is HR MHR coating on one of the hypotenuses. The prisms required) . WHR Metal
TFP [nm] AOI method PR λ 157 Rp<0.3%, Rs>87% 72° on CaF2 EBE DPR 193 Tp>80%, Ts<10% 73° EBE BBPR 248 Tp>80%, Ts<2% Brewster EBE VA CP 266 Tp>90%, Ts<2% Brewster EBE PR GOC 355 Tp>94%, Ts<2% Brewster EBE Tp>96%, Ts<0.2% Brewster IBS 532 Tp>96%, Ts<1% Brewster IAD LP BBPOL Tp>99%, Ts<0.1% Brewster IBS SP 808 Tp>95%, Ts<1% Brewster EBE NF 940 Tp>95%, Ts<1% Brewster IAD MP 1064 Tp>95%, Ts<5% 45° cube EBE Filter BP Tp>99%, Ts<1% 45° IBS REF Tp>95%, Ts<2% Brewster EBE Tp>99%, Ts<0.1% Brewster IBS 1342 Tp>96%, Ts<1% Brewster IAD TFP 1550 Tp>98%, Ts<1% 45° IBS CP 2100 Tp>95%, Ts<0.5% Brewster IAD BBPOL Polarizer [nm] extinction ratio AOI method The extinction ratio can be optimized 1064λ Tp/Ts > 990 Brewster IBS for use in reflection or transmission. Rs/Rp > 200 The given values refer to the standard TFP Tp/Ts > 48 Brewster EBE made by IBS and the much cheaper EBE. Rs/Rp > 20 Also other splitting ratios, e.g. Tp/Rs VA can be optimized. GOC GP Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 47 Polarizer
Examples
100 100 T % T % 80 80 70 70 60 60 p x 10 p s x 10 s s p 50 50 40 40 30 30 20 20 10 10 0 0 980 990 10001010 1020 1030 1040 1050 1060 nm 1080 760 800 840880 920 960 1000 1040 nm 1120
TFP 1022-1038 nm /55.4° [B-14497] HT 808 nm TFP 1064 nm /45° [B-11055] 1022-1038 nm: Tp > 98.5%, Ts < 0.1% (IBS-coating) 808 nm: Ru < 5%; 1064 nm: Rs > 99.6%, Rp < 5% (IBS-coating)
100 100 p T % s x 10 R % 80 80 s 70 70 60 60 s 72° both sides coated 50 50 40 40 30 30 20 20 p 10 10 0 0 400 500 600700 800 900 1000 1100 1200nm 1400 600 650 700750 800 850 900 950 1000 nm 1100
BBPOL 470-1090 nm /45° S-TiH3-cube [B-06332] BBPOL 750-850 nm / 72 ± 2° [B-08032] 470-1090 nm: extinction ratio > 1000 (IAD-coating) 750-850 nm: 72°: Tp, avg > 97%, Rs > 75%; 70-74°: Tp, avg > 95%, Rs > 75%
100 100 T % p T % 80 80 70 70 60 60 s p 50 50 40 40 30 30 20 s 20 10 10 0 0 500 600 700 800 900 1000 nm 1100 1000 11001200 1300 1400 1500 1600 nm
TFP 515-532 nm + 1030-1064 nm /65° [B-13591] HR 1064 nm TFP 1565-1579 nm / 55 ± 1° [B-11854-01] 515-532 nm + 1030-1064 nm: Ts < 0.2%, Tp, avg > 98% 1064 nm: Ru > 99%; 1565-1579 nm: Rs > 99.5%, Tp > 98%; (IBS-coating) 1572 nm: Tp/Ts ≥ 100 (IBS-coating)
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Variables Variable Attenuators (VA/IVA)
Coating types
VAR Variable Attenuators VA LASEROPTIK offers AVACS (Automatic Variable DAR Change transmission by tilting of edge filters, Attenuator Control System). The unit is driven TAR with highest transmission at AOI 0°, mainly by a stepper motor and can be controlled AR BBAR produced to work in the range from AOI 0° to manually or by a computer. The AVACS in- MAR 45°. cludes power supply, control display, opera- WAR tion elements, starting routine, limit stop de- Inversely Variable Attenuators IVA vice, computer interface and water cooling. Work in the same way as VA but have lowest HR transmission at AOI 0°. Additionally a simple housing with manual DHR adjustment can be supplied. BBHR Given tolerances show the minimum tuning HR MHR range in transmission. Beam displacement can WHR be compensated by using a second plate or Metal two filters simultaneously. For low attenuation we recommend an AR-coated second plate.
PR DPR BBPR VA VA [nm] 0° -> 45°; T= method PR λ GOC 157 70% -> 2% on CaF2 EBE 10% -> 70% on CaF2 EBE inversely (IVA) 193 80% -> 10% EBE LP 248 90% -> 2% standard EBE SP 95% -> 1% high power MS NF 10% -> 95% high power MS inversely (IVA) MP 266 92% -> 1% standard EBE Filter BP 95% -> 1% high power MS REF 355 92% -> 1% standard EBE 92% -> 1% non-shifting IAD 532 92% -> 1% standard EBE TFP 90% -> 1% non-shifting IAD CP 808 95% -> 1% non-shifting IAD BBPOL 940 95% -> 1% non-shifting IAD Polarizer 1064 95% -> 1% EBE 95% -> 1% non-shifting IAD 1550 95% -> 1% EBE 2940 90% -> 1% on CaF2 EBE
VA GOC GP GNF Variables GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 49 Variables
Examples
100 100 0°
T % T % 80 15° 80 25° 70 70 35° 60 60 45° s 50 50 u 40 40 p 30 30 20 20 10 10 0 0 900 9409801020 10601100 1140 1180 1220 nm 1300 0 5 020151 25 30 35 40 AOI [°] 50
VA 1064 nm /0-45° T 95-1% [B-00431-01] VA 1064 nm / 0-45° T 95-1% [B-00431-01] 1064 nm: 0° -> 45°; T = 95% -> 1% Angle resolved transmission at 1064 nm
100 100
T % 45° T % 80 80 35° 70 70 25° p 60 60 15° 50 50 u 0° s 40 40 30 30 20 20 10 10 0 0 225 230 235240245 250 255 260 265 nm 275 0 5 020151 25354030 AOI [°] 50
IVA 248 nm / 15-45° T 10-95% [B-01991] IVA 248 nm / 15-45° T 10-95% [B-01991] 248 nm: 15° -> 45°; T = 10% -> 95% (MS-coating) Angle resolved transmission at 248 nm
Beam dump AR VA or IVA
Toothed wheels VA or IVA AR
Compensated Attenuator AVACS [M-00013] Scheme Automatic Variable Attenuator Control System
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Gradient Output Couplers and Filters
Coating types
VAR A special machine setup is required to ma - Given tolerances show the minimum variation DAR nufacture gradient optics that allow the central on a standard substrate 50x27 mm if the plate TAR wavelength to change with its position on the is shifted within about 40 mm (right-middle- AR BBAR substrate. So it is possible to change the opti - left position). MAR cal properties without any beam displacement WAR by shifting a rectangular plate across the beam.
HR DHR BBHR HR MHR WHR Metal
PR DPR BBPR VA GOC [nm] right–> left T = method Gradient Output Coupler GOC PR T λ λ GOC 1 193 1% -> 70% MS Changes the reflection-transmission-ratio. left right
middle 532 85% -> 25% IAD λ 1064 25% -> 75% IAD LP Gradient Pass Filter GP SP The incoming light passes through in one posi- NF GP [nm] right–> left T = method tion and will be blocked in the other one, avail- λ MP λ 532 1% -> 95% IAD GLP able as long pass GLP and short pass GSP. Filter T BP 1 1064 1% -> 95% IAD GLP left right REF λ 95% -> 1% IAD GSP If a GLP and GSP are used in combination, the resulting bandwidth can be varied in a large wavelength area. TFP CP BBPOL GNF [nm] right–> left T = method Gradient Notch Filter GNF λ λ λ 808-914 1% -> 90% IAD Transmits one wavelength and blocks another Polarizer T 1 1 976-1064 0.5% -> 90% IAD one in left position and reversely in right posi- λ left right tion.
VA GIF [nm] right–> left T = method Gradient Interference Filter GIF λ GOC λ λ 476-514 on request IAD Gives the opportunity to select various wa ve - T GP 1 2 lengths, e.g. for fast external change of multi- GNF left right λ line noble gas ion lasers. Variables GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 51 Variables
Examples
100 100
T % T % 80 80 70 70 60 60 left middle right left middle right 50 50 40 40 30 30 20 20 10 10 0 0 185 187 189191 193 195 197 199 201 nm 205 500 510 520 530 540 550 560 nm 580
GOC 193 nm /0° [B-00810] GOC 532 nm /0° [B-05980] 193 nm: right -> left position; T= 1% -> 70% (MS-coating) 532 nm: right -> left position; T = 85% -> 25% (IAD-coating)
100 100
T % T % 80 80 70 70 60 60 left middle right left middle right 50 50 40 40 30 30 20 20 10 10 0 0 490 500 510520 530 540 550 560 570 nm 590 970 990 1010 1030 1050 1070 1090 1110 1130 nm 1170
GLP 532 nm /0° [B-05986] GSP 1064 nm /0° [ B-05984] 532 nm: right -> left position; T= 1% -> 95% (IAD-coating) 1064 nm: right -> left position; T = 95% -> 1% (IAD-coating)
100 100
T % T % 80 80 70 70 60 60 left right left middle right 50 50 40 40 30 30 20 20 10 10 0 0 760 780 800820 840 860 880 900 920 nm 960 460 470 480 490 500 510 520 nm 540
GNF 808-914 nm /0° [B-05991] GIF 476-514 nm /0° [ B-06004] 808 nm: right -> left position; T = 90% -> 1%; tolerances on request (IAD-coating) 914 nm: right -> left position; T = 1% -> 90% (IAD-coating)
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Reflection Filters
Coating types
VAR Reflection Filters REF LASEROPTIK offers two different housings to ad - DAR Select wavelengths by using 4 filter plates si- just the black filter plates (NG1) between AOI 15° TAR multaneously. By tilting the pla t es the transmit- and 60°: AR BBAR ted wavelength area can be selected with no – a manually driven unit, equip ped with plates MAR change of the final beam direction. 50 x 50 x 1 mm, and WAR – a stepper motor driven unit, controlled manu- Listed below are scanning range , half band- ally or by PC, with 70 x 50 x 3 mm. width HBW and transmission at peakΔλ maximum HR Tmax of standard REFs. Please ask for more details. DHR BBHR The manufacturing of variable reflection filters HR MHR is possible for a spectral range from 140 nm to WHR 2000 nm. Metal Typically the scanning range is about 15% of the center wavelength, with rejection <10-4 from PR VUV to FIR and damage threshold similar to DPR high power coatings. BBPR VA PR GOC REF [nm] HBW [nm] Tmax method type Δλ180-200 12 80% EBE 1 235-275 18 90% EBE 1 LP 40 95% EBE 2 SP 290-340 20 95% EBE 1 NF 340-390 25 98% MS 1 MP 500-585 30 98% IAD 1 Filter BP 750-880 60 98% IAD 1 REF 1000-1150 60 95% IAD 1
TFP CP BBPOL Polarizer
VA GOC GP GNF Variables GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 53 Variables
Examples
100 100
R % R % 80 80 70 70 60 60 intensity after 4 reflections intensity after 4 reflections 50 50 40 40 30 30 20 20 10 10 0 0 200 220 240 260 280 300 320 nm 340 200 220 240 260 280 300 320 340nm
REF 248 nm /45° Type 2 [B-01931] REF 266 nm /45° Type 2 [B-04555] 248 nm: R4 > 95%, compensation of manufacturing tolerance for 266 nm: R4 > 95%, compensation of manufacturing tolerance for wavelength by angle tuning necessary. wavelength by angle tuning necessary.
100 100
R % R % 80 80 70 70 60 60 intensity after 4 reflections intensity after 4 reflections 50 50 40 40 30 30 20 20 10 10 0 0 310 320 330 340350 360 370 380 390 nm 410 300 400 500 600 700 800 900 nm
REF 355 nm /45° Type 1 [B-03442] REF 532 nm /45° Type 2 [B-06179] 355 nm: R4 > 95%, compensation of manufacturing tolerance for 532 nm: R4 > 98%, compensation of manufacturing tolerance for wavelength by angle tuning necessary. wavelength by angle tuning necessary.
100
R % 15° 80 30° 70 45° 60 60° intensity after 4 reflections 50 40 30 20 10 0 350 400450500 550600 650 700 nm 800
Reflection Filter Housing REF 532 nm /45° Type 2 [B-06179] motor driven (left) [M-00012] and manual adjustment [M-00042] 532 nm: R4 > 98%, compensation of manufacturing tolerance for wavelength by angle tuning necessary.
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Metal coatings
Coating types
VAR 100 DAR %
TAR R Al-VUV AR BBAR 80 MAR 70 WAR 60 Al Rh Pt Au Cr 50 Ag HR 40 DHR 30 BBHR 20 HR MHR WHR 10 Metal 0 0.1 0.150.20.3 0.40.6 0.8 1.0 1.5 2.0 3.0 µm 5.0
PR Metal coatings have a fair but very broad re - Al – Aluminium shows the highest reflectance DPR flectivity over a certain wavelength range. in the UV. A reflection dip occurs around 850 BBPR nm due to phonon absorption. VA LASEROPTIK offers standard mirror coatings PR GOC such as aluminium, gold or silver, normally With a fluoride protection layer Al coatings can with protection layer or even enhanced, i.e. be optimized for use in the VUV. with an additional dielectric coating system. LP Ag – Silver coatings give the highest reflectivity SP in the VIS and NIR. As they have low GDD in a NF broad wavelength area they can be taken as MP Al-VUV Al-VIS-IR Ag Au simple and low-priced mirrors for femtosecond Filter BP Metal [nm] R > R > R > R > lasers. REF λ 120 65% 157 65% Au – Gold shows poor adhesion to glass and 193 70% needs a bonding layer of chromium. It is often TFP 220 75% used in the far IR without a protection layer or CP 300 80% 80% as a solderable coating. BBPOL 450 85% 95% 532 88% 96% Polarizer Other metal coatings are available too, e.g. 808 80% 97% 97% chrome, chrome-nickel or platinum . 940 87% 97% 97% 1064 92% 97% 97% 1550 92% 97% 98% VA 2940 92% 97% 97% GOC GP GNF Variables GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 55 Metal coatings
Examples
100 100 R % R % 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 200 400 600800 1000 12001400 16001800 nm 2200 300 400 500600 700 800900 1000 1100 nm 1300
Al + Protection Layer - VIS-IR [B-00018-01] Al enhanced 532 nm /45° [B-08462] > 300 nm: R ± 3% vs. curve 532 nm: R > 97%
100 100 R % R % 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 200 400 600800 1000 12001400 1600 1800 nm 2200 200 400 600800 1000 12001400 1600 1800 nm 2200
Ag + Protection Layer [B-00931] Ag enhanced HR 650-1350 nm for fs /45° [B-10662-02] 450-500 nm: R > 95%; 500-1100 nm: R > 97% 650-1350 nm: Ravg > 98%
100 100 R % T % 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 200 400 600800 1000 12001400 1600 1800 nm 2200 300 400 500600 700 800900 1000 1100 nm 1300
Au + Protection Layer [B-06039] Metallic Filter T 20% [B-02754] IR: R > 97% 550 nm: T20 ± 3%
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Optical Parametric Oscillators OPO
Coating types
VAR MHR An Optical Parametric Oscillator (OPO) trans - resonator can be used for additional fine- DAR forms a pump laser wave with the frequency tuning. With an OPO it is possible to achieve TAR p into two different waves, called idler and wa ve lengths beyond those of available laser AR BBAR sωignal, where signal is the one with the higher me diums. MAR frequency. The sum of their frequencies ( i ω WAR LP and s) is equal to the frequency of the pump An OPO system uses several different coating ω laser: p = i + s ty pes. In the following you can find the dia - ω ω ω gram for different OPOs. To minimize the los - HR Basically an OPO is a nonlinear crystal working ses in intensity every untitled surface has to DHR inside an optical resonator where either the be coated with a corresponding AR . BBHR idler wave or the signal wave resona tes. HR MHR NF Of course there are other possible setups WHR By modifying phasematching properties like for the featured systems, especially when Metal the orientation or the temperature of the crys - wor king with 45°-filters and optimized polari - tal you can change the frequency of the output. za tion for the pump, signal and idler wave. Another option is to modify its quasi-phase - PR matching period through a perio di cal poling. Please find more information regarding OPO DPR A variation in the optical path length of the coatings with optimized GDD on page 70. BBPR VA PR GOC ... IR OPO HR 1.064 µm Pump 1.064 µm
LP Signal OPO crystal Idler SP 1.4-1.8 µm 2.6-4.4 µm NF MP Filter BP REF HR or PR HR 1.064 µm HR 1.064 µm HR 1.4-1.8 µm 1.4-1.8 µm HT 1.4-1.8 µm HT 1.4-1.8 µm HT 2.6-4.4 µm HT 2.6-4.4 µm TFP Two examples of an OPO set-up CP BBPOL BBO OPO HR 355 nm Pump Polarizer 355 nm Signal BBO crystals Idler 410-710 nm 710-2600 nm
VA GOC HR or PR HR 355 nm HR 355 nm HR 410-710 nm GP 410-710 nm HT 410-710 nm HT 410-2600 nm HT 710-2600 nm Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 57 OPO
Examples
100 100 T % T % 80 80 70 70 60 60 x 10 50 50 40 40 30 30 20 20 10 10 0 0 1000 1500 2000 2500 3000 3500 nm 4000 9001100 1300 1500 1700 nm 1900
HT 1064 HR 1480-1650 HT 3000-3800 nm /0° CaF2 [B-05749] HR 1064 nm HT 1300-1800 nm /45° [B-01392] 1064 nm: R < 8%; 1480-1650 nm: Ravg > 99.7%; 1064 nm: R > 99.6%; 1300-1800 nm: R < 10% 3000-3800 nm: Ravg < 20%
100 100 T % T % 80 80 70 70 60 60 p s 50 50 40 40 30 30 20 20 10 10 0 0 300 700 1100 1500 1900 2300 nm 2700 300 700 1100 15001900 2300 nm 2700
HR 410-700 nm HT 725-2600 nm /0° [B-03084] HR 410-710 nm/s HT 710-2650 nm /p /45° [B-05259] 410-700 nm: Ravg > 99%; 725-2600 nm: Ravg < 10% 410-710 nm: Rs,avg > 99%; 710-2650 nm: Rp, avg < 2% (IAD- coating)
100 10 T % R% 80 8 70 7 60 6 50 5 40 4 30 3 20 2 10 1 0 0 300 350 400450 500 550600 650 nm 750 300 350 400450 500 550600 650 700 nm 800
HR 355 nm HT 400-700 nm /45° [B-11634] AR 355 nm + 400-700 nm /0° [B-03316] 355 nm: R > 99.5%; 400-700 nm: Ravg < 4% (IBS-coating) 355 nm: R < 1%; 400-700 nm: Ravg < 1.2%
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Multi-line coatings
Coating types
VAR MAR The growing laser market requires more and 100
DAR more complex coatings working simultane - %
T TAR ously at many different wavelengths with 80 AR BBAR different optical requirements. 70 MAR 60 WAR Besides standard multi-line coatings descri- 50 MHR bed in previous chapters, e.g. Combinations 40 of harmonics (see page 40) and OPO (see 30 HR page 56), LASEROPTIK offers customized DHR coatings. 20 BBHR 10 HR 0 MHR For difficult multi-line coatings normally IBS 400 450500 550 600 650nm 700 WHR MP will be the appropriate coating technique of Metal choice as it com bines highest precision in Even extraordinary wishes can be fulfilled, only film growth and thermal stability. the sky is the limit...
PR Besides transmission or reflection of course optimized, see the following chapter “Disper - DPR other optical properties like GD or GDD can be sive coatings”. BBPR VA PR GOC 100 100 %
R %
80
70 R 60 80 LP 50 SP 40 70 30 measured NF 20 10 60 MP 0 Filter 200 300400500 600700 800 900 nm 1100 BP 50 100 + comp uted %
40
REF R 80 70 30 60 50 20 TFP 40 30 10 CP 20 10 0 BBPOL 0 200 300400500 600700 800 900 nm 1100 200 300 400 500 600 700 800 900 nm 1100 Polarizer Sometimes it is necessary to use different filter the rear surface for superposition of the deu - coatings on a pair of substrates or on the front terium and halogen lamp spectra. As shown, and rear surface of an optic. the measured reflection (red line) complies with the computed values (black line). This VA The example above has a broadband long wave proofs the high precision of the IBS-coating GOC pass coated on the front and a gain flattener on technique. GP Variables GNF GIF
All values are given for standard coatings. Customized coatings available for all types.
Coating methods available:
EBE IAD IP MS IBS 59 Multi-line coatings
Examples
100 100 T % T % 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 1000 11001200 1300 1400 nm 1500 450500550 600 650 700 750 800 nm 900
R 10% 1064-1079 nm R 45% 1330 nm R 90% 1440 nm /0° T 5% 500 nm linear to HT 800 nm /45° [B-14140-01] [B-10328-01] 500 nm:T± 2%; linear progress with about (avg) ± 2% vs. curve; 1064-1079 nm: R ± 2% vs. curve; 1320-1340 nm + 1430-1450 nm: 800 nm: T > 98% (IBS-coating) R ± 5% vs. curve (IBS-coating)
100 100 T % T % 80 80 70 70 60 60 50 50 40 40 30 30 20 20 10 10 0 0 350 450 550 650 750 850950 1050 nm 1250 600 800 1000 1200 1400 1600 1800 nm 2000
HR 360-390 nm PR 410-680 nm HR 720-1100 nm /0° HT 630 nm HR 750-1470 nm HT 1535 nm HR 1600-1800 nm /0° [B-14638] [B-04390] 360-390nm: T < 1%; 410-680nm: gain flattening filter; 633nm: T > 30%; 750-1470nm: Tavg < 0.5%; 1535nm: T > 90%; 720-1100nm: T < 1% (IBS-coating) 1600-1800nm: Tavg < 1% (IBS-coating)
100 100 T % T % 80 80 70 70 60 60 s p 50 50 40 40 30 30 20 20 10 10 0 0 430 460 490 520 550 580 610 640 nm 350 450 550 650 750 850 950 1050 nm
HT 460 nm + 525 nm HR 532 nm HT 630 nm HR 637 nm /45° HR 399 nm HT 532-578 nm HR 660 + 759 nm HT 1064 nm /45° [B-10107-01] [B-13566] 460nm: Rp < 2%; 525nm: Rp < 8%; 532nm: Rs > 98.5%; 630nm: 399 nm: R > 99.5%; 532-578 nm: Ravg < 0.5%; 660+759 nm: Rp < 8%; 637nm: Rs > 97% (IBS-coating) R > 99.8%; 1064 nm: R < 0.5% (IBS-coating)
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Dispersive coatings
The phase velocity of a light wave travelling The dispersion management is highly depen - through optical materials depends on the wa - ding on the coating design and a sub-nanome- velength. This phenomenon is called chroma - ter manufacturing accuracy for GDD optimized tic dispersion. optics. At LASEROPTIK, this precision is ensu - red by the sophisticated method of Ion Beam As a critical requirement for the generation of Sputtering (IBS, see page 27 for details). ultrashort pulses (e.g. in femtosecond lasers) and for controlling the pulse shape, dispersive With the help of an optical in-situ process dielectric optics are needed to compensate the control based on the calculated design, the group- delay dispersion (GDD) which is introdu - deposition of complex, custom tailored stacks ced by other components such as the laser of many (n > 70) non quar terwave layers is per- crystal. formed. The results are verified ex-situ by in- house GDD measurements and are used for The GDD is defined as the derivate of the reengineering of the coating design. group delay with respect to the angular fre- quency, or the second-order derivate of the LASEROPTIK uses both custom-built and com- phase. mercial GDD measurement setups ranging from 500 nm to 1650 nm (see measuring methods Of course all dispersive elements inside the on page 113), whereas dispersive mirrors can be re sonator have to be taken into account for produced up to 4.5 µm, optimized and charac- op timizing the total GDD (see also the Group terized for GDD by retrograde analysis of the Velocity Dispersion of standard substra tes gi ven coating thickness data. on page 94). Otherwise the different delays of various frequency components within a short pulse result in – pulse broadening – generation of satellites in the time-domain and – loss of peak power.
Mirrors may have either low (i.e. close to zero) GDD or a tailored non-zero GDD. As shown in the following sections, there are different types of coating designs. LASEROPTIK offers:
• mirrors with low or optimized GDD • highly dispersive narrow bandwidth mirrors, so-called GTI mirrors • chirped mirrors and matched pairs Keep it ultrashort • octave-spanning broadband chirped mirrors with our dispersive mirrors with moderate GDD for ultrafast applications! • partial reflectors • coatings used with an OPO
For example, these coatings compensate the dispersion introduced by other components like the laser crystal in a laser cavity. Or they serve as compressors in chirped pulse amplifi- cation systems (CPA).
In general, various spectral requirements can be combined with a GDD value as target for coating design and production, e.g. for OPO optics or partial reflectors.
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Low GDD mirrors After having managed to produce short laser which may cause problems in applications pulses, it is necessary to propagate these puls- with high average power. es without disturbing the temporal beam pro- file. This is the moment where low dispersive Alternatively dielectric mirrors can be optimi - beam steering mirrors enter the game. zed for low GDD. They offer very low losses avoiding thermal problems but normally have Often metal mirrors (see page 54) like gold or a near-zero GDD only for a limited spectral special enhanced silver mirrors are the most bandwidth. To overcome this, it is possible to economical solution while having low disper- make use of the concept of chirped mirror sion. pairs.
The major drawbacks of these mirrors are limit- All low GDD coatings can be designed on cus- ed reflectivity and higher absorption los ses, tomer request, see examples:
Examples
100 50 40 T % 0° 0° 80 30 70 20 60 10 x 10 50 0 40 10 Phi'' [fs²] 30 20 20 30 10 40 0 50 850 900 950 10001050 1100 1150 nm 1250 960 98010001020 1040 1060 1080 1100 nm 1140
HR 1020-1040 nm /0-10° low GDD [B-11072] 1020-1040 nm: R > 99.9%; | GDD (R) | < 20 fs² (IBS-coating)
100 200
T % 150 80 100 70 60 50 50 0
40 Phi'' [fs²] -50 30 -100 20 10 -150 0 -200 940 960 9801000 1020 1040 1060 nm 1100 1000 1020 10401060 1080 nm 1100
HT 970-982 nm T 7.5% 1035-1055 nm /0° low GDD [B-11872] 970-982 nm: R < 5%; 1035-1055 nm: R ± 1% (IBS-coating) 63 Dispersive coatings
Examples
100 50 40 T % 80 30 70 20 60 10 x 100 50 0
40 Phi'' [fs²] 10 30 20 20 30 10 40 0 50 850 900 950 10001050 1100 1150 nm 1250 960 98010001020 1040 1060 1080 1100 nm 1140
R 99.5% 990-1090 nm /0° low GDD [B-12042] 990-1090 nm: T ± 0.15%; | GDD (R) | < 10 fs² (IBS-coating)
100 250 200 T % 80 150 70 100 60 50 x 100 50 0
40 Phi'' [fs²] -50 30 -100 20 -150 10 -200 0 -250 700 750 800 850 900 950 nm 1000 740 760780 800820 840860 880 900 nm 940
HR 760-910 nm /45°p low GDD [B-12162] 760-910 nm: Rp > 99.8%; | GDD (Rp) | < 50 fs² (IBS-coating)
100 20
R % 15 80 10 70 60 5 50 0
40 Phi'' [fs²] -5 30 -10 20 10 -15 0 -20 300 400 500 600700 800 900 1000 1100 nm 1300 300 400 500600 700 800 900 1000 1100 nm 1300
Ag enhanced 450-1000 nm [B-11437] 450-1000 nm: R > 90%; Ravg > 97%
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GTI mirrors GTI mirrors are basically Bragg mirrors with ad - GTI mirrors may be equipped with additional ded and precisely adjusted spacer layers in the features like a pass band for the pump laser or upper section of the film stack which work like a tailored transmittance, so they can be used a Gires-Tournois-Interferometer (GTI). as out-coupling mirrors. A typical application is the dispersion management in Ytterbium Resonances introduced by the spacer layers based lasers. can produce very high GDD values but these
are limited: The higher the GDD, the smaller 0 the spectral bandwidth (see curves of three -750 fs² different GTI mirrors on the right). -1000 -1300 fs²
-2000 LASEROPTIK offers GTI mirrors with GDD values -2900 fs²
up to about 5000 fs². Even higher values are Phi'' [fsec²] -3000
possible but will lead to increased optical -4000 losses and lower LIDT. 1000 1010 1020 1030 1040 1050 nm 1060
Examples
100 0 -100 T % 0° 0° 80 -200 70 -300 60 -400 x 10 50 -500
40 Phi'' [fs²] -600 30 -700 20 -800 10 -900 0 -1000 850900 950 1000 1050 11001150 nm 1250 980 1000 1020 1040 1060 nm 1080
HR 1010-1060 nm: R > 99.9%, GDD -500 fs² [B-12654] 1010-1060 nm: R > 99.9%, GDD ± 150 fs² (IBS-coating)
100 0 -500 T % 0° 0° 80 -1000 70 -1500 60 -2000 x 10 50 -2500
40 Phi'' [fs²] -3000 30 -3500 20 -4000 10 -4500 0 -5000 850900 950 1000 1050 1100 1150 1200 nm 1300 1000 1010 1020 1030 1040 1050 nm 1060
HR 1030 nm /0-5° GDD -2900 fs² [B-08609] 1030 nm: R > 99.95%, GDD (R) ± 500 fs² (IBS-coating) 65 Dispersive coatings
Examples
100 0
T % -100 80 -200 70 60 -300 x 10 50 -400
40 Phi'' [fs²] -500 30 -600 20 10 -700 0 -800 960 980 1000 1020 1040 1060 nm 1100 1000 1020 1040 1060 1080 nm 1100
HT 980 nm T 2.6% 1055 nm /0° GDD -600 fs² [B-11395] 980 nm: T > 95%; 1055 nm ± 8 nm: R ± 0.25%, GDD ± 60 fs² (IBS-coating)
100 0 -200 T % 80 -400 70 -600 60 -800 x 10 50 -1000
40 Phi'' [fs²]-1200 30 -1400 20 -1600 10 -1800 0 -2000 940 9609801000 10201040 1060 nm 1100 1000 1010 1020 1030 1040 1050 nm 1060
HT 976 nm T 5% 1030 nm /0° GDD -1300 fs² [B-12655] 976 nm: T > 95%; 1030 nm: T ± 1%, GDD ± 250 fs² (IBS-coating)
100 200 180 T % 80 160 70 140 60 120 x 10 50 100
40 Phi'' [fs²] 80 30 60 20 40 10 20 0 0 1700 18001900 2000 2100 2200 2300 nm 2500 1800 18501900 1950 2000 2050 2100 nm 2200
HT 1900-2100 nm / 0° GDD +100 fs2 [B-12656] 1900-2100 nm: R > 99.9%, GDD ±15 fs2 (IBS-coating)
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Chirped mirrors and matched pairs One can think of a chirped mirror as a Bragg It is possible to produce chirped mirrors span- mirror where the thickness of the layers slowly ning more than one optical octave and having increases or decreases from bottom to top, so extra features like a high transmission pum - that the different “colours” are reflected at dif- ping pass band. ferent depths resulting in different group de- lays which gives a non-zero GDD. LASEROPTIK's cooperation with leading re- search institutes in the field of ultrashort la sers There are unavoidable residual GDD oscilla- and frequency combs helps to generate new tions of such mirrors. If necessary they can be results about the produ cibility of complex GDD sup pres sed for example by using chirped mir- coatings of which some findings are pub- ror pairs where the oscillations of two different lished.* mirrors cancel each other out.
* Chia, S.-H., Cirmi, G., Fang, S., Rossi, G. M., Mücke, O. D., Kärtner, F. X., Two-octave-spanning dispersion-controlled precision optics for sub-optical-cycle waveform synthesizers, in: Optica, Vol. 1 (2014), Iss. 5, pp. 315-322
Examples
100 200
T % 0° 150 80 0° 100 70 60 50 x 10 50 0 40 Phi'' [fs²] -50 30 -100 20 10 -150 0 -200 500 600 700 800 900 1000 1100 nm 1300 600650 700 750 800 850900 950 1000 nm 1100
HT 532 nm HR 650-1100 nm /0-15° GDD opt. [B-10888] 532 nm: T > 95%; 650-1100 nm: R > 99.9%; 780-1010 nm: GDD (R) = -88 -> 0 fs² ± 50 fs² (IBS-coating)
100 250 200 T % 80 150 70 100 60 50 x 10 50 0
40 Phi'' [fs²]-50 30 -100 20 -150 10 -200 0 -250 600 650 700750 800 850900 950 nm 1050 650 700 750 800 850 900 950nm1000
HR 730-930 nm /7° p GDD -125 fs² [B-12658] 730-930 nm: Ravg > 99.9%, GDD ± 40 fs² vs. theoretical curve (IBS-coating) 67 Dispersive coatings
Two examples for chirped mirror pairs
100 100 T % T % 80 80 70 70 60 60 x 10 x 10 50 50 40 40 30 30 20 20 10 10 0 0 500 600 700 800 900 1000 nm 1100 500 600 700 800 900 1000 nm 1100 [B-09709-P01] [B-09709-P02]
100 250 90 200 80 150 70 100 P01 P02 60 50 P02 P01 mirror pair 50 0 mirror pair
Phi' [fs] 40
Phi'' [fs²] -50 30 -100 20 -150 10 -200 0 -250 650 700 750800 850 900 950 nm 1050 650 700 750 800850 900 950 nm 1050
HT 532 nm HR 675-975 nm /7° p GDD opt. [B-09709-P01+02] target specifications for a mirror pair, best effort (IBS-coating): 532 nm: T > 98%; 675-975 nm: Rp > 99.9%, GD (R)-ripple < 2 fs
100 0 -10 T % 80 -20 P01 70 -30 60 -40 x 10 x 10 50 -50 P02 mirror pair 40 Phi'' [fs²] -60 30 -70 P01 P02 20 -80 10 -90 0 -100 550 600 650700 750 800850 900 nm 1000 650 700 750 800 850 900 nm 950
HR 700-900 nm /7° s GDD opt. [B-09813-P01+02] 700-900 nm: Ravg > 99.9%; 710-860 nm: GDD ± 10 fs² (IBS-coating)
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Example for chirped mirror pairs with combination of positive and negative GDD
1.0 A combination of positively and negatively chirped mirrors
T % gives low average dispersion 0.8 while having significantly 0.7 lower absorption losses than 0.6 metal mirrors. P02 mirror pair P01 0.5 0.4 0.3 0.2 0.1 0.0 700 800 900 1000 1100 1200 nm 1400
80 300
70 200 60 100 50 P02 mirror pair mirror pair 40 0 Phi' [fs] 30 Phi'' [fs²] P01 -100 20 P01 P02 -200 10
0 -300 700 800 9001000 1100 1200 nm 1400 700800 9001000 1100 1100 nm 1400
HR 830-1230 nm /45° s GDD opt. [B-12544-P01+02] 830-1230 nm: R > 99.8%, GD = const ± 3 fs, GDD = 0 ± 30 fs² (IBS-coating)
Chirping by nature: House cricket (lat. Acheta domesticus) 69 Dispersive coatings
Partial Reflectors In the Ti:Sapphire range and other bands, tightly toleranced partial reflectors are needed to split the beams or to couple out a certain proportion while keeping the GDD under control.
Examples
100 200
T % 150 80 100 70 60 50 50 0
40 Phi'' [fs²] -50 30 -100 20 10 -150 0 -200 800 850 900950 1000 10501100 1150 1200 nm 1300 800 850 900 950 1000 1050 11001150 1200 nm 1300
R 83% 1020-1040 nm /0° low GDD [B-11074] 1020–1040 nm: R ± 0.5% vs. curve; | GDD (R) | < 20 fs² (IBS-coating)
100 200
T % 150 80 100 70 60 50 x 10 50 0
40 Phi'' [fs²] -50 30 -100 20 10 -150 0 -200 600 700 800 900 1000 1100 nm1200 600700 800900 1000 1100nm 1200
R 99% 690-1050 nm /20° p low GDD [B-11214] 690–1050 nm: R ± 0.25% (goal ± 0.1%) vs. curve (IBS-coating)
100 200
T % 150 80 100 70 60 50 50 0
40 Phi'' [fs²] -50 30 -100 20 10 -150 0 -200 650 700 750 800 850 900 950 1000nm 1100 650700 750800 850900 950 1000 nm 1100
T 1-25% 680-1010 nm /0° low GDD [B-11263] Tolerance for transmission: ± 0.2% absolute or ± 10% of target value (IBS-coating)
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OPO coatings
Optical Parametric Oscillators (OPO) also con- tical components into the total system and vert radiation of femtosecond lasers and allow consequently more GDD that has to be mana - tunable lasing in other wavelength ranges (see ged. The diagrams demonstrate some exam- page 56). This conversion introduces more op- ples of GDD optimized OPO coatings. Examples
100 500 400 T % 80 300 70 200 60 100 x 10 Calculated without absorption losses in FS 50 0
40 Phi''-100 [fs²] 30 -200 20 -300 10 -400 0 -500 500 100015002000 25003000 3500 nm 4500 900 10001100 12001300 1400 1500 nm 1700
HT 750-850 nm HR 980-1620 nm HT 1750-4500 nm /4° GDD opt. [B-11613] 750-850 nm: Tp > 96%; 980-1620 nm: Rs,avg > 99.8%; 1750-4500 nm: Tp,avg > 80% (IBS-coating)
100 250 200 T % 80 150 70 100 60 50 x 10 50 0
40 Phi'' [fs²] -50 30 -100 20 -150 10 -200 0 -250 500 100015002000 25003000 3500 nm 4000 600 650700 750800 850900 950 1000 nm 1100
HT 515-532 nm HR 650-1000 nm HT 1100-4000 nm /0° GDD opt. on YAG [B-07321] best effort (IBS-coating)
100 500 400 T % 80 300 70 200 60 100 x 10 50 0 40 Phi''-100 [fs²] 30 -200 20 -300 10 -400 0 -500 600 800 10001200 1400 1600 1800 nm 2200 600 650700 750800 850900 950 1000 nm 1100
HT 532 nm HR 700-1000 nm HT 1100-2100 nm /0° low GDD [B-11546] 532 nm: R < 5%; 700-1000 nm: R > 99.9%; 1100-2100 nm: T > 90% (IBS-coating) 71 Dispersive coatings
Others While all the coatings shown before are specifi- Example cally designed for dispersion control there usu- ally is the need for more kinds of optical filters. 100
When working with femtosecond laser pulses it T % is important to know at least their dispersion. 80 On request, we are able to provide dispersion 70 information even for our coatings which are not 60 optimized in this regard. p s 50 The example shows a thin film polarizer (TFP) 40 at 1030 nm with GDD tolerances for the reflect- 30 ed and transmitted wavelength. 20 10 0 960 980 1000 1020 1040 1060 1080nm 1100
100 500 80 400 Tp (without substrate) Tp (without substrate) 60 300 40 200 20 100 Rs 0 0 Rs Phi' [fs]
-20 -100Phi'' [fs²] -40 -200 -60 -300 -80 -400 -100 -500 960 980 10001020 1040 1060 1080nm1100 960 980 1000 1020 1040 1060 1080nm1100
TFP 1030 nm /55.4° [B-06289] 1030 nm: Rs > 99.98%, Tp > 99%
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Coatings on special substrates
Crystals, wafers and metals LASEROPTIK has long-term experiences in coa - LASEROPTIK has approved coating processes ting on almost every type of substrate. Besides in place including pre- and after-treatment for standard glasses and crystals like Fused Silica, a broad variety of laser and non-linear crystals CaF2, MgF2, other common types e.g. crown e. g. common materials like BBO, BiBO, COB, glass or flint glass made by SCHOTT, CORNING, CTA, KDP, KGW, KTA, KTP, KYW, LBO, LiNbO3, HOYA, NIKON or OHARA, we offer optimized Ruby, RTA, RTP, Spinell, TGG, YAB, YAG, YAP, coating designs and techniques, substrate han- YLF, YVO4, Sapphire, diamond and many oth- dling and coating fixtures especially for: ers. Dedicated rimless fixtures are developed and built in our workshop. Coatings for wafers and similar materials (e. g. Ge, Si, SiC, GaAs) are also available.
LASEROPTIK offers a selection of coatings on me tals like Fe, Cu, Al. All processes are optimi - zed for best optical performance and highest Please note: adhesion. For an effective and fast overview,Laser Oallptik coa - tings in this catalog areor in given our for standard Online Portal LOOP substrate materials (mostly Fused Silica or CaF2).
For quotations for coatings on special sub- strates we have to know: • refractive index Fixed fibers • allowed maximum temperature • thermal expansion coefficient • size
Every coating design and process can be adapted to each substrate type. Please choose the best matching coating and ask us for a quotation with an optimized one. 73 Coatings on special substrates
Fibers UHV windows Naked or fully confectioned fibers can be coat- For coatings on UHV windows LASEROPTIK de- ed in holders that are individually manufactu - veloped approved tooling as well as pre- and red in the workshop in-house. In a rather “cold” after-treatment processes. Standard holders for pro cess like Ion Beam Sputtering (IBS) or Mag - the most common sizes from CF16 up to CF160 ne tron Sputtering (MS) the coating of fibers is are available. done, e.g. to achieve the evidently lowest re- flectivities for AR. The coating process will be adapted to the al- lowed maximum temperature and thermal gra- For MS some meters of fibers can be hidden in dient. Because of technical limitations UHV the spaciouse drum or elsewhere behind the windows normally can only be coated with EBE exposed surface. Even lower temperatures can technique. be realised with IBS. Adapted fixturing is avail- able for a wide range of fiber optics. The usual shadow-effects from the metal-flan- ge will be reduced as far as technically possible in order to coat the maximum of the optical sur- Glass cells face. Our experiences show that a coating will work in an area of about Ø 9 mm for CF16, Ø 29 Glass cells / cuvettes have to be coated on up mm for CF40 and Ø 57 mm for CF63 and will not to five sides. They require specially designed be centred exactly in the middle. substrate holders and optimized coatings. Please note: With the experiences of more than 30 years, LASER OPTIK developed a technique to achieve For an effective and fast overview all coa t - LaserOptik a maximum clear aperture and reliable fixtures. ings in this catalog or in our Online Portal LOOP are given for standard Standard UHV windows: CF40, CF63, CF100 substrate materials (mostly Fused Silica or CaF2).
For quotations for coatings on glass cells or UHV windows we have to know: • allowed maximum temperature • glass material (mostly Fused Silica, Kodial or Sapphire) • size
Every AR coating can be adapted to each substrate type. Please choose the best matching coating and ask us for a quota- tion with an optimized one.
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Large optics LASEROPTIK uses dedicated equipment for di- effects to a minimum. The uniformity can also electric coatings on large optics up to 2 m in be adapted to radii of curvature, e.g. of cylin - length (long axis for rectangular shapes) or 1 m dri cal lenses. in diameter with a superior spectral uniformity over the complete surface and high LIDT val- A variance in central wavelength of below ± 1% ues. Approved automated ultrasonic and man- can be achieved for optics up to 2000 mm in ual cleaning procedures are deployed to guar- length. The 8 measured curves below show the antee an optimum cleanliness also on these excellent uniformity on a large optic (long axis > large scale geometries. The possible sizes are 1300 mm) coated with an IBS broadband AR. listed in the table below. A tailored environment made of separated coating rectangular round cleanrooms, dedicated inspection metrology technique long axis short axis* and optics' cleaning solutions was built for and IBS 2000 mm 250 mm 250 mm around the innovative equipment. It is part of a IAD 1200 mm 120 mm 1000 mm department that specializes in large round and EBE 940 mm 80 mm 300 mm rectangular optics, addressing highest de- *at given maximum of long axis, can be larger with shorter mands for LIDT, losses and spectral perform- long axis. ance.
The uniformity of the coatings is a critical fac- A space-resolved quality inspection is perfor - tor for applications in industrial laser systems med on the whole dimension for surface de- for laser beam expansion or in projects for gra - fects and spectral properties. Large optics are vitational and petawatt laser research. Coating being escorted in custom-built lifting and hand - design, inner architecture of the machine and ling tools for inspection, transportation and fix- in-situ process control help to reduce gradient ing in the coating machine.
Uniformity of an IBS coating on a large optic 1.0 (BBAR 342-412 nm /0°) R % 0.8
0.7
0.6 positions: 0-1400 mm 0.5 intervals: 200 mm
0.4
0.3
0.2
0.1 0.0 320 340 360 380 400 420 440nm 460
“Maxima”, the patented IBS coating machine for large optics 75 Coatings for special applications Coatings for special applications
Extremely low loss laser optics So called supermirrors in ring laser gyroscope been measured at the Fraunhofer Institute for assemblies or certain scientific applications re- Applied Optics and Precision Engineering in quire coated optics with extremely low losses Jena and achieved a value of TSB = 1.1 ppm. At (i.e. absorption and scattering). a typi cal absoption and residual transmission These mirrors also have a maximum reflectivity of together < 15 ppm this equals a reflectivity of with R > 99.998 % and total losses < 10 ppm. at least 99.998%. For longer wavelengths even 99.999% has been achieved which is very close LASEROPTIK uses a modified IBS machine that to the perfect laser mirror with R = 100%. is capable to produce coatings on superpoli - shed substrates. The cleanliness of the machi - The results have been confirmed by LASER - ne and environment is maintained in a dedica- OPTIK’s in-house cavity ring-down setup and ted super-clean room, where also the ex ten sive scatter measurement. The use of super-poli shed substrate pre- and after-treatment takes place. substrates with a surface roughness < 1 Å rms is essential for the values mentioned above. Their Measurement devices such as whitelight pro- quality is inspected with a white light profilo - filometers and high resolution microscopes (up meter. Below some mea sured values: to x 1000) for the inspection procedures are in place. A custom built cavity ring-down setup al- Scatter TSB Absorption Reflection CRD lows to determine the reflection with a preci- HR 532 nm /0° 4.9 ppm 1) (int. ARS) 10.2 ppm 2) > 99.997% 2) (T~5ppm) sion of up to four decimal places and to refer HR 633 nm /0° 1.1 ppm 1) > 99.998% (T~5ppm) back to the losses. HR 1064 nm /0° (< 1 ppm) 3) < 2 ppm 4) > 99.999% (T~5ppm) HR 2940 nm /0° 24 ± 12 ppm 6) 99.994% 5) (T=36 ppm) The total back scattering (TSB, as referred to in 1) Measured at IOF Jena; 2) Measured at LZH; 3) Calculated ISO 13696) of a supermirror at 633 nm taken from surface roughness; 4) Measured at ILT Aachen; from LASEROPTIK’s current production has 5) measured by customer; 6) 1-R-T
A view into our super-clean room
Typical gyro mirrors
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Spaceborne/airborne optics Operating a laser system under high-vacuum MS and IBS coatings withstand extreme tem - conditions in space requires environmentally perature ranges and working conditions requi - robust coatings and optics. red for airborne laser optics. Additionally we test the resistancy of specific coatings against The key risk factors for failure are laser-induced gamma and neutron radiation for use in space. contamination and coating degradation. You Environmental testing can be done by LASER - have to exclude increasing absorption, coating OPTIK or one of our partner institutes. destruction or delamination due to cosmic, so- lar or laser radiation before sending out flight As part of the extensive qualification program, optics.1) laser optics and coatings underwent several LIDT tests which simulated space conditions. In various projects2) for DLR, ESA and NASA or DLR and LZH3) performed for example damage their industry partners, LASEROPTIK has devel- tests under vacuum conditions. See below for oped coatings and optics for laser applications the results for an UV space laser HR 355 nm/s in space or airborne environments and proven HT 532 nm/p + 1064 nm/s /45° with an AR on their functionality and durability. the rear surface, measured in vacuum:
30 40 2 2 J/cm J/cm 30 0% LIDT @ 1064 nm 0% LIDT @ 355 nm 20 0% LIDT @ 532 nm 25 15 20 LIDT = 20.4 ± 5.1 J/cm2 LIDT = 13.6 ± 2.0 J/cm2 15 10,000 10 10,000 10 5 LIDT = 10.8 ± 2.7 J/cm2 5 10,000 0 0 10 100 1000 pulses 10000 10 100 1000 pulses 10000
Technical data: LIDT with 10,000 on 1 LIDT, References and further reading: vacuum 2 x 10-6 mbar, repetition rate 100 Hz. 1) Wernham, D. (2011): Optical coatings in space, in: Proc. Pulse duration: 3 ns (355 nm); 6.5 ns (532 nm); SPIE 8168, Advances in Optical Thin Films IV, 81680F (04. 12 ns (1064 nm). Oct. 2011). Beam diameter: 160 µm (355 nm); 280 µm (532 nm); 310 µm (1064 nm). 2) Cosentino, A.; Selex Galileo S.p.A., Rome, Italy; D'Ottavi, A.; Sapia, A.; Suetta, E.: Spaceborne lasers development for ALADIN and ATLID instruments, Geoscience and Remote Sensing Symposium (IGARSS), 2012 IEEE International
3) Riede, W.; Allenspacher, P.; Lammers, M.; Wernham, D., Ciapponi, A.; Heese, C.; Jensen, L.; Maedebach, H.; Ristau, D. (2013): From ground to space: How to increase the con- fidence level in your flight optics, in: 45rd Annual Laser Damage Symposium on Optical Materials for High Power Lasers, 8885. SPIE Laser Damage, 22.-25. Sep. 2013, Boulder, USA. 77 Coatings for special applications
Natural environmental influences: radiation - cold - pressure - humidity - heat
If it is not possible to achieve the desired flatness with the chosen coating technique or design there are two further options but some more effort is required: A specially designed coating on the rear surface can compensate the stress of the main coating. This rear side coating can also be optimized for extra fea- tures like a high transmission pass band.
The most extensive way for stress compen - sation is to use pre-curved substrates. They ha ve to be manufactured with a curvature adap ted exactly to the computed stress of the coat ing, so standard substrates cannot be used anymore.
Coatings for harsh environments Coatings by mother nature
As described in the section ‘spaceborne/ 35 airborne optics’, IAD and sputtered coatings (IBS and MS) withstand hostile working condi- tions, such as extreme temperature ranges or R % high humidity. 25 20 Magnetron sputtered coatings also have been successfully tested in customer projects 15 as being resistant to several gases, acids and C. limbata C. aurigans other fluids. 10
5 Optimizing flatness 0 300 350 400 450 500 550 600 650 nm 750 Stress in thin films may cause a slightly de- formed surface, concave if the stress is ten- sile, convex if it is compressive. The easiest Steep natural edge filter / partial reflector on way to avoid deformation is to use thicker dorsal elytra of Chrysina lim bata and Chrysina substrates but often this is not possible. aurigans 1
LASEROPTIK has approved coating processes 1) Campos-Fernández, C. et al., Optical Materials Express, in place that help to reduce stress in the Vol. 1, Iss. 1, pp. 85-100 (2011) coating and to avoid unwanted (a)spherical effects for substrates with extraordinary flat- ness requirements.
Additionally, the stress can be reduced sig- nificantly by optimizing the coating design. Taking the Stoney equation into account, the number and thickness of the layers can be adapted to the size and elastic properties of the substrate. But this may lead to a higher total film thickness and reduced spectral per- formance. For optimizing coating processes LASEROPTIK has a dedicated machine with an optional in-situ interferometer.
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Substrates
Production Tolerances Characteristics and transmission curves Group Velocity Dispersion (GVD) Reflection of an uncoated surface Stock substrates 80 back to Contents Substrates
Production of substrates
Raw glass Cutting Chamfering edges
Pre-cut in rough shape Cut into blanks Chamfer sharp edges by grinding or milling
• from a melt (Fused Silica) • by diamond-studded • prevents handling dam- or a crystal boule (CaF2, blades ages and gives a cleaner Sapphire) appearance • for round optics: edge • made at glass companies grinding or CNC milling into • done in an early stage like Schott, Heraeus, round and plano blanks to avoid damaging during Ohara, Corning later ones • for curved optics: premanu- • a stock of common glass facture radius by CNC pro- types from different suppli- cessing ers is available for quick turnaround • the alternative to proces - sed blanks are preformed moulded blanks 81 Production of substrates
Grinding Polishing Cleaning Inspection
Approach the dimensional Polish to our standard P4 Clean off processing residues Inspect for all given speci- tolerances fi cations
• after fine grinding the sub- • using pitch as carrier for the • using multi-frequency ultra- • tolerances see next pages strate still is intransparent, polishing agent leads to a sonic and various baths but already has precise very good surface qua lity with different chemical • measuring methods see dimensions add-ons page 112 • using a polishing foil can • quality aspects like paral - reduce process time and • details about automatic le lism, radius or surface costs significantly and can ultrasonic and manual figu re are already being get to similar results cleaning on page 110 moni to red throughout the process • poli shing for super-poli - shed optics (roughness • CNC combines several < 1.5 Å rms) can take twice grinding steps in one ma- as long chining center • CNC can help in all stages to handle larger quantities and to reduce processing times and cost 82 back to Contents
Tolerances for substrates
LASEROPTIK has a wide selection of sizes and materials in stock but can also provide nearly every custom optic manufactured to your indi- vidual needs.
For a quotation we need to know at least the following information: • material • quantity and size • for curved surfaces: radii of curvature • used aperture
If we do not get any other information we will choose standard quality properties and stan- dard tolerances.
Please note: the quality of the substrate has to be chosen with the specifications of the coat- ing in mind. For example low loss mirrors need to have substrate surfaces with a low micro- roughness. You can of course use super poli - shed optics for a standard mirror, but that might be a waste of money. Our standard pol- ishing quality is P4.
It is common to accept tolerances for substrate size but also for variations of surface form and surface imperfections. Nevertheless some ap- plications require more precise specifications.
In the next columns you can find a description of how to specify substrates according to DIN ISO 10110.
Code number 0 Material imperfections: Stress birefringence (DIN ISO 10110-2) • specified as 0/A • where A is the maximum allowable stress birefringence in nanometers per centimeter of optical path length, e.g. 0/5
Code number 1 Material imperfections: Bubbles and inclu - si ons (DIN ISO 10110-3) • specified as 1/N x A • where N is the number of bubbles and inclu- sions with a maximum allowable size A, e.g. 1/3 x 0.010 83 Tolerances for substrates
Code number 2 Code number 6 Material imperfections: Inhomogeneity and Laser irradiation damage threshold striae (DIN ISO 10110-4) (DIN ISO 10110-17) • specified as 2/A;B • specified as 6/ • where A denotes the inhomogeneity class • For more information regarding the LIDT see and B denotes the striae class, e.g. 2/5;5 page 114.
Code number 3 Code number 13 Surface form tolerances (DIN ISO 10110-5) Wavefront deformation tolerance • specified as 3/A (B/C) (DIN ISO 10110-14) • where A is the maximum permissible sagitta • specified as 13/A (B/C) deviation, B is the maximum permissible • where A is the maximum permissible sagitta irregularity (deviation from sphere) and C is deviation (single pass), B is the maximum the fine surface figure error (rotational sym- permissible irregularity (single pass) and C is metry irregularities), e.g. 3/0.2(0.1/0.2) the permissible rotation-invariant irregularity • please see DIN ISO 14999 for more detailed (single pass), e.g. 13/0.2 (0.1/0.2) information. • please see DIN ISO 14999 for more detailed information. Commonly the surface form tolerance is stated as flatness and transferred into values of the The above explanations of DIN ISO 10110 are measuring wavelength (e.g. 633 nm), as simplified. For more information please see the shown in the following table.λ Please note that complete text of DIN ISO 10110. the achievable flatness strongly depends on the diameter-thickness-ratio of the substrate. Another way to specify substrates is to use the MIL-norms. A comparison between MIL and 3/0.1 3/0.2 3/0.5 3/1 3/2 DIN ISO is very difficult and reveals that the DIN /20 /10 /4 /2 ISO 10110 provides finer levels for decisi ons. λ λ λ λ λ Code number 4 For the standard surface quality of our sub - Centring tolerances (DIN ISO 10110-6) stra tes we can give you the following values: • specified as 4/ • where denotesσ the maximum permissible clear aperture according to DIN ISO 10110-7 according to MIL-0-13830A wedge σangle by spherical surfaces, e.g. 4/3’ up to Ø surface imperfections Scratch/Dig1) 12.7 mm 5/3 x 0.025; L1 x 0.001 10 / 5 Code number 5 25 mm 5/3 x 0.025; L1 x 0.001 10 / 5 Surface imperfection tolerances 50 mm 5/3 x 0.025; L1 x 0.001 10 / 5 (DIN ISO 10110-7) 75 mm 5/3 x 0.040; L1 x 0.001 20 / 10 • specified as 5/N x A 100 mm 5/3 x 0.063; L2 x 0.001 20 / 10 • where N is the number of allowed surface im- 1) Please note: The scratch/dig information in accordance with MIL-13830 shall apply for a maximum perfections with maximum size A, e.g. inspection area of Ø 20 mm. 5/3 x 0.025 • other codes represent additional errors: C stands for coating imperfections, L for Please contact us, if you require higher quality scratches with any length and E for chips standards. • a possible complete nomenclature would be 5/3 x 0.025; C3 x 0.025; L1 x 0.001; E 0.2 • please see DIN ISO 14997 for more detailed information 84 back to Contents Substrates
Right, the data sheet for the standards of specification for our uncoated substrate S-00010 according to DIN ISO 10110. 85 Tolerances for substrates
For special customer-owned substrates (e.g. For choosing the correct substrate size it might crys tals) we additionally need to know the fol - be useful to think about the possible aperture lowing properties: and about the holders used for the coating • maximum temperature we can use while process: coating • If not described otherwise we use holders • thermal expansion coefficient with r ims (normally covering about 2% of the • refractive index dia meter, minimum 0.5 mm) which will re - • incompatibility e.g. with certain cleaning sol- main uncoated. vents • If the coating has to be rimless, small defects caused by the clamp holder and overspray LASEROPTIK has decades of experiences in can occur on the sides of the substrates. coa ting on all kind of substrates and a large data base, but we gratefully accept any addi - We do have over 10,000 substrate holders tional information about the characteristics of avail able and can work with nearly all sizes. Of your substrates. course we will find a special holder system for your substrates if necessary.
Looking for amusement after so much theoretical input? 1. The coatings engineer's life and the coating itself should be low of this 2 2. Assistant for many coating methods 3. No coating without… 4. Optical pattern for single stack de - 12 1_ 3 signs 12 5. Not only expensive watches have it 7 6. Natural reflection at an interface 11 1 named after him 10 7. Will be done between cutting and grinding 6 8. Best angle for separating s and p po - larized light 9. Change transmission with the angle 9 of in cidence 4 10. Measured by a Twyman-Green inter - 4 5 fero meter 6 3 11.Fast delivery 12. Name of the LaserOptik Online Portal. 5 13. Home of high power optics and coatings
7 11 13 13 9 10
2
8 8
1 2 3 4 5 6 7 8 9 10 11 12 13 86 back to Contents Substrates
Standard substrates Characteristics and transmission curves
Overview of the characteristics of the most common substrates
useable transmission range refractive index thermal expansion coefficient VUV UV– MIR [nm] nd n 20–300°C [10–6/°C] NIR 588 nm 2940 nm α Borofloat® x 350–2000 1.471 – 3.3 CaF2 xxx130–8000 1.434 1.418 18.9 Duran® x 350–2000 1.473 – 3.3 FS–UV x 180–2000 1.458 – 0.55 FS–IR xx250–3500 1.458 1.421 0.55 Ge x 2000–12000 – 4.053 6.1 LiNbO3 1) xx380–4500 2.3 2.162 2.to 14 MgF2 1)xxx120–6000 1.377 1.364 8.5 to 14 N-BaK2® x 350–1800 1.54 – 9.1 N-BK7® x 350–2000 1.517 – 7.1 N-SF11® x 380–2500 1.785 – 6.8 N-SF6® x 380–2500 1.805 –9 PYREX® (Corning 7740) x 400–2200 1.474 – 3.3 Quartz (crystal) 1) x 200–2300 1.544 1.501 7.8 to 14.2 S-PHM 52 x 420–1800 1.618 – 12 S-TIH53 x 550–1800 1.847 – 10.4 Sapphire 1) x x 220–5000 1.768 1.713 5.to 7 Si x 1250–12000 – 3.437 4.2 ULE® (Corning 7972) x 400–2000 1.483 – < 0.1 YAG 2) x x 300–4000 1.837 1.787 7 Zerodur® x 550–2500 1.542 – < 0.1 ZnSe xx550–20000 2.624 2.438 7.6
Reference values, with no guarantee 1) birefringent, all values refer to the ordinary ray 2) undoped
Please note: LASEROPTIK has a wide selection The trademarks used in this chapter of sizes and materials in stock. are trademarks owned by the following companies: We also can provide nearly every custom optic, manufactured Corning Inc. according to your specific needs. Duran Group GmbH Using standard substrates can Heraeus Holding GmbH help to hold down the total cost j-fiber GmbH Nikon Corporation and lead time. Ohara Corporation Schott AG 87 Standard substrates
Please note: The cur ves below show exter- nal transmission and include the fresnel reflection losses of the poli shed surfaces. With high quality antireflection coatings these losses can be eliminated for selected wave- Transmission curves of optical glasses and crystals length ranges.
Nonlinear scaling 100 T%
LiF 3 mm
UV-CaF2 YAG und. 3 mm 50 3 mm MgF2 3 mm UV-FS 3 mm IR-FS N-BK7 ZnSe 3 mm 3 mm 3 mm Sapphire 3 mm
0 0.1 0.15 0.2 0.3 0.4 0.6 0.8 µm 1.0
Nonlinear scaling 100 T%
ZnSe IR-FS UV-CaF2 3 mm 3 mm 3 mm
50 Si Ge 3 mm 2 mm UV-FS N-BK7 YAG und. Sapphire 3 mm 3 mm 3 mm 3 mm
0 1.0 1.5 2.0 3.0 4.0 6.0 8.0 µm 10.0
Nonlinear scaling 100 T%
KRS 5 1 mm Ge ZnSe 2 mm 3 mm 50
Si 3 mm
0 10 15 20 30140 50 60 80 µm 00 88 back to Contents Substrates
Most customers' needs can be met with two standard materials: FS-UV and FS-IR.
Fused Silica-UV (amorphous silicon dioxide) is produced syn- 100 thetically from high purity silicon by flame hy- drolysis. It differs by its high UV-transmittance
T % from natural Fused Silica, molten from crystal- line quartz. UV-FS offers: 1 mm • broad transmission range 3 mm 6mm UV-FS • low thermal expansion coefficient, providing 50 high thermal stability and resistance to ther- 10 mm mal shocks • thermal operating range up to 800 °C • great hardness and resistance against scratches • very high resistance to radiation darkening • absence of bubbles and impurities 0 0.150.16 0.17 0.18 0.19 1.5 2.0 2.5 3.03.5 4.0 µm 5.0 There is a wide range of different substrate ma- terials available, varying in homogeneity, gra - Transmission curve of UV Fused Silica des of laser induced fluorescence and content of bubbles, inclusions and OH. LASEROPTIK of- ten uses SQ0, SQ1 (former Q0, Q1, Q2), Su pra - sil® 1+2, Corning 7980® or NIFS-U®.
In the UV-range we recommend to use optimi - zed materials like SQ0/SQ1 E-193 or E-248 for lowest losses. Other materials can be supplied as well.
Fused Silica-IR IR absorption of FS is caused by OH-chemical 100 bond content, most relevant at wavelengths near the water absorption band at 2.7 µm but
T % also critical at 940 nm. Reduction in OH can be assured by melting high quality quartz or spe- cial manufacturing techniques, but mostly at 1 mm the sacrifice of UV transmittance. 3mm IR-FS 50 A common material is Infrasil®. For high power applications, especially in the range of the OH- waterbands we recommend a material with ® 6mm 10 mm lowest OH-content, like Corning 7979 , Suprasil® 300 or Suprasil® 3001 + 3002.
0 0.15 0.20 0.25 0.30 1.0 1.5 2.0 2.5 3.03.5 4.0 µm 5.0
Transmission curve of IR Fused Silica 89 Standard substrates
N-BK7® is a frequently used optical glass, a chemically stable borosilicate crown glass, molten in ce- 100 ramic vessels to be free of Platinum impurities.
Normally N-BK7® has a more instable polishing T % and is softer than FS, so the surface can be da - maged easier. Unfortunately often defects will only become visible after the cleaning process. 1 mm 6 mm N-BK 7 Additionally N-BK7® has higher losses through 50 higher absorption and scattering and therefore 3mm 10 mm cannot be used for high power applications.
These are the reasons why LASEROPTIK recom- mends using Fused Silica instead and offers N- BK7® or equivalent substrates only on request. 0 0.25 0.3 0.35 1.5 2.0 2.5 3.03.5 4.0 4.5 5.05.5 µm 6.5 Low expansion glasses Transmission curve of N-BK7® If applications require low thermal expansion and FS will be too expensive, commonly the fol- lowing materials are used: Boro float®, Duran®, Pyrex® (Corning 7740). Glass materials with a thermal expansion coefficient lower than FS and close to zero are for example ULE® (Corn- ing 7972) or Zerodur® .
But all glasses have a limited transmission range (see table on page 86).
Glasses with special refractive index LASEROPTIK can supply all sizes of nearly all common substrate materials, like all types of flint glass or crown glass. For these normally we use optical glasses from Schott, Ohara or Hoya. On customer request we can of course also work with the material of other manufacturers. We can for example provide a refractive index between nd = 1.487 (S-FSL5) and nd = 2.00 (S-LAH 79).
Optical filter glasses We can also supply and/or coat on optical filter glass (mainly from Schott), which works as na - tural filter, for example as band-, long- or short- pass filter. A number of different colorants and concentrations can be provided on request. 90 back to Contents Substrates
Sapphire (crystalline Al2O3) is free of absorption in the range 240 nm - 4 µm. 100 Optical components generally have c-cut (0001-orientation). T % It stands out by strength, hardness, chemical and thermal stability and is often used as high 1 mm pressure and high tempe ra ture window materi- 6 mm Sapphire al and for viewports. 50 3mm Compared to Fused Silica it has 20 times high- er heat conductivity. In addition it is insoluble in most common acids.
LASEROPTIK offers ultrahard coatings that par- allel the material hardness and allow best en- 0 vironmental durability. 0.12 0.16 0.20 0.24 3.25 4.0 4.75 5.5 6.25 7.0 7.75 8.5µm 10.0
Transmission curve of Sapphire (cryst. Al2O3) YAG undoped
Yttrium Aluminium Garnet (Y3Al5O12) has near- 100 ly the same IR transmission as Sapphire, but is not birefringent and has a high optical homo- T % geneity.
It is pulled from the melt in the same manner 1 mm as the Nd:YAG rods by Czochralski me thod, 3mm YAG und. which produces high quality crystal line boules 50 without any inclusions and bubbles. Due to a 6mm special thermal treatment, the YAG material has a minimum of internal stress.
0 0.19 0.25 0.31 0.37 3.25 4.0 4.75 5.5 6.25 7.0 7.75 8.5µm 10.0
Transmission curve of YAG undoped 91 Standard substrates
Fluorides Fluorides have a very broad transmission range from VUV to FIR. They must be chosen 100 especially if the coating materials will also be fluorides, like often used in the VUV/UV or in T % the MIR/ FIR. The main materials are MgF2 and 1 mm CaF2. 2 mm
MgF2 is the fluoride with the highest resistan- 5 mm MgF2 ce to degradation by atmospheric moisture, al- 50 so at higher temperatures. Its hardness, rug ged - ness and resistance to mechanical and thermal shock is advantageous for laser windows.
MgF2 has a low birefringence. The windows are fabricated with the optical axis as symmetry ax- is, minimizing the birefringence effect (c-cut). 0.12 0.16 0.20 0.24 4.05.0 6.0 7.08.0 9.0 10.0 11.0 µm 13.0 LASEROPTIK's MgF2 substrates are very resis - tant to F-center formation due to their low O2- Transmission curve of Magnesium Fluoride contamination, which is also expressed by the high VUV transmission.
CaF2 is used as window as well as substrate 100 material. Compared to MgF2 it has an isotropic structure, lower hardness and it is sensitive to T % thermal shocks. If CaF2 windows are protected 1 mm from humidity, they can be used for several years in the laboratory. CaF2 begins to soften at 600 °C, the reaction with atmospheric mois- 2 mm CaF2 ture will take place above this temperature. 50 5 mm Especially in the VUV/UV-range we recommend to use optimized materials for lowest losses like 157 nm- or 193 nm-grade.
The curves on the right show the transmission of the standard UV-grade. 0 0.12 0.16 0.20 0.24 4.0 5.0 6.0 7.08.0 9.0 10.0 11.0 µm 13.0
Transmission curve of Calcium Fluoride 92 back to Contents Substrates
Si (Silicium) is often chosen as a substrate material for high 100 power mirrors, making use of its high thermal conductivity. But it can be used for windows in T % the whole FIR range up to some 100 µm.
1 mm Si 50 3 mm
6 mm 10 mm
0 1.0 1.05 1.1 1.15 1.26.0 10.0 14.0 18.0 22.0 26.0 30.0 µm
Transmission curve of Silicium ZnSe (Zinc Selenide)
is a standard material for use in CO2 lasers as 100 windows, beamsplitters, output couplers or fo- cussing lenses. Because of its broad transmis- T % sion range, its low absorption and scatter, ZnSe is a standard material for use from 500 nm up to 22 µm. ZnSe is nonhygroscopic, chemically stable unless treated with strong 1 mm 3 mm ZnSe acids, and has a very high damage threshold. 50 6 mm LASEROPTIK offers a large selection of AR, reflecting and beamsplitter coatings on ZnSe.
0 0.450.50 0.55 0.60 10.0 14.0 18.0 22.0 26.0 30.0 µm
Transmission curve of Zinc Selenide 93 Standard substrates
Ge (Germanium) is commonly used in imaging systems and in- struments in the 2-12 µm range. Ge is utili zed 100 as a substrate for lenses, windows and output couplers for low power cw as well as pulsed T % CO2-lasers. It is also a popular choice as a sub- strate for a variety of infrared filters. Ge is non- toxic and nonhygroscopic, has good thermal conductivity and excellent hardness. 1 mm Ge 50
3 mm 6 mm
0 1.7 1.8 1.9 2.010.0 14.0 18.0 22.0 26.0 30.0 µm
Transmission curve of Germanium 94 back to Contents Substrates
Group Velocity Dispersion (GVD) of standard substrates
For special applications the dispersion of the substrates 250 becomes important. 200 The two diagrams show the dispersion curves of four com - ]
mon substrate materials: m
m 150 / ²
s Sapphire (ord.) For coatings with optimized f [ FS dispersion properties see D 100 V BaF2 chapter “Dispersive coatings “, G starting on page 61. 50 CaF2
0 0.3 0.4 0.50.6 0.7 0.8 0.9 1.0 1.1µm 1.2
Dispersion of plane substrates, AOI 0°
100 BaF2 0 -100 CaF2
] Sapphire (ord.)
m -300 m / ² s f
[ FS
D -500 V G
-700
-900 1 1.21.4 1.6 1.8 2 2.2 2.4 2.62.8 µm 3
Dispersion of plane substrates, AOI 0° 95 Standard substrates
Reflection of an uncoated surface
The reflection of an uncoated surface decreas- es the transmission of an optic. So windows 35 need an anti-reflecting coating on both sides. Si R % R Optics with a filter coating on the front surface 25 need an AR on the rear surface as well which is often forgotten in customer’s requests. ZnSe 20 The example, right, shows the reflection of an 15 uncoated surface depending on the refractive LiNbO3 index of the substrate. 10 SF6
The values are calculated from the Fresnel 5 FS SF5 equations with an angle of incidence AOI = 0° CaF2 BK7 and against air, so the reflection becomes: 0 MgF2 n-1 2 1 1.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0 refractive index 3.8 R = _____ n+1 ( ) Reflection of an uncoated surface The values for the given materials refer to a wavelength of 1064 nm.
The impact of polarization changes with the 100 angle of incidence. The diagram shows the re- flection for different polarizations depending R % on the AOI for Fused Silica against air at 1064 nm.
Please notice that working with p-polarized uncoated FS vs. air light and the Brewster angle (arctan(n), for FS 50 AOI = 55.4°) the reflection falls down to zero and no antireflective coating will be necessary. This effect is used for TFP rear surfaces. s u p
0 0 10 20 30 40 50 60 70 80AOI° 90
Reflection of an uncoated surface 96 back to Contents Substrates Please note:
Discount for stock substra - tes of the same type: 10 pieces 5 % Stock substrates 20 pieces 10 % 30 pieces 15 % 50 pieces 20 %
Material refractive indices LASEROPTIK stocks substrates for coatings in Most orders of our customers can be met with the wavelength range from 120 nm to 50 µm. FS-UV and FS-IR. For these we offer a large Only the highest grade materials are used in num ber of plane and curved substrates. the production of the components. In our standard sizes we can offer Fluorides as Nevertheless most optics are custom made at MgF2 and CaF2. For CaF2 we offer four different unique requirements and drawings. So please qualities (VUV-grade for 157 nm, UV-grade for feel free to send your individual specifications. 193 nm or 248 nm and VIS-IR quality).
All substrates are manufactured at high quality For applications with an absorption free range specifications in order to keep critical optical up to 4 µm, Sapphire or undoped YAG is re- properties as scattering, absorption or beam commended. Both materials are very hard and deviation at a minimum. Besides flatness and withstand temperatures up to 1.000 °C as well roughness, the surface imperfections are an- as high pressure. other critical parameter. ZnSe is a standard material for use from 500 nm Listed on the following pages LASEROPTIK up to 22 µm, because of its broad transmission stocks a selection of UV- and IR-transmitting range, its low absorption and scatter. substrates for fast delivery. A brief characteri- zation of the substrates is given for every type.
Refractive index (nm) MgF2 CaF2 FS Sapphire YAG ZnSe for each stock substrate mate- λ ord. ray ord. ray undoped rial, listed for different wave- 157 1.468 1.558 1.661 –– – lengths. 193 1.428 1.502 1.561 1.927 – – 248 1.403 1.468 1.509 1.847 –– 266 1.399 1.462 1.500 1.833 – – 308 1.392 1.453 1.486 1.811 – – 337 1.389 1.448 1.479 1.801 – – 355 1.387 1.446 1.476 1.796 2.020 – 450 1.381 1.439 1.466 1.779 1.855 – 488 1.379 1.437 1.463 1.777 1.847 2.775 514 1.378 1.436 1.462 1.773 1.844 2.715 532 1.378 1.435 1.461 1.772 1.842 2.687 588 1.377 1.434 1.458 1.768 1.837 2.624 633 1.376 1.433 1.457 1.766 1.833 2.591 800 1.374 1.431 1.453 1.761 1.824 2.524 1064 1.372 1.429 1.450 1.755 1.818 2.482 1320 1.371 1.427 1.447 1.750 1.812 2.465 1540 1.370 1.426 1.444 1.747 1.810 2.456 2100 1.368 1.424 1.437 1.735 1.802 2.445 2940 1.364 1.418 1.421 1.713 1.787 2.438 4000 1.351 1.410 1.389 1.675 1.760 2.433 Reference values, with no guarantee 97 Stock substrates
Plane windows Diameter Thickness Flatness Surface UV-FS price IR-FS price Ø mm t mm (633 nm) imp. tol. Article-No. in € Article-No. in € 32λ /10 5/3 x 0.025 S-00265 40 S-00945 62λ/10 5/3 x 0.025 S-00909 45 S-00402 50 6.35 4 λ/10 5/3 x 0.025 S-00910 45 S-00946 82λ/10 5/3 x 0.025 S-00350 45 S-00947 λ 10 0.5 /2 5/3 x 0.040 S-00614 S-00948 Ø t λ 10 1 /4 5/3 x 0.025 S-00911 45 S-00949 Wedge < 5 min. of arc 10 2 λ/10 5/3 x 0.025 S-00912 S-00950 10 5 λ/10 5/3 x 0.025 S-00609 45 S-00951 50 Tolerances 12.7 2 λ/10 5/3 x 0.025 S-00264 45 S-00952 Diameter Ø: + 0.0/-0.1 mm 12.7 3 λ/10 5/3 x 0.025 S-00323 45 S-00401 55 Thickness t: ± 0.1 mm Parallelism/Wedge: < 5 min. of arc 12.7 5 λ/10 5/3 x 0.025 S-00913 45 S-00953 λ Chamfer: 0.1- 0.3 mm x 45° 12.7 6.35 /10 5/3 x 0.025 S-00018 45 S-00027 55 Clear aperture: > 80% 15 6.35 λ/10 5/3 x 0.025 S-00914 S-00954 λ Surface imperfection tolerance: 19 3 /10 5/3 x 0.025 S-00915 50 S-00955 acc. to DIN ISO 10110-7 19 4.5 λ/10 5/3 x 0.025 S-00295 55 S-00956 19 6.35 λ/10 5/3 x 0.025 S-00163 55 S-00957 20 2 λ /4 5/3 x 0.025 S-00644 55 S-00958 20 5 λ/10 5/3 x 0.025 S-00916 55 S-00959 22.4 5 λ/10 5/3 x 0.025 S-00917 55 S-00960 25 0.5 λ 5/3 x 0.040 S-00600 50 S-00961 25 1 λ/2 5/3 x 0.025 S-00617 50 S-00962 25 2 λ/4 5/3 x 0.025 S-00499 45 S-00500 25 3 λ/4 5/3 x 0.025 S-00028 45 S-00501 70 25 5 λ/10 5/3 x 0.025 S-00321 50 S-00964 25 6.35 λ/10 5/3 x 0.025 S-00010 50 S-00025 75 25.4 6.35 λ/10 5/3 x 0.025 S-00035 55 S-00965 25 9.5 λ/10 5/3 x 0.025 S-00409 60 S-00966 30 2 λ /4 5/3 x 0.025 S-00918 60 S-00967 30 6 λ/10 5/3 x 0.025 S-00919 65 S-00968 30 8 λ/10 5/3 x 0.025 S-00920 S-00969 38 3 λ /4 5/3 x 0.025 S-00502 85 S-00972 38 5 λ/4 5/3 x 0.025 S-00922 85 S-00973 38 6.35 λ/10 5/3 x 0.025 S-00923 85 S-00974 38 9.5 λ/10 5/3 x 0.025 S-00924 90 S-00975 40 5 λ/10 5/3 x 0.025 S-00925 85 S-00397 45 2 λ /2 5/3 x 0.025 S-00926 85 S-00976 45 6.5 λ/10 5/3 x 0.025 S-00927 95 S-00977 50 1 λ 5/3 x 0.040 S-00734 100 S-01115 50 2 λ/2 5/3 x 0.040 S-00735 105 S-00979 50 3 λ/4 5/3 x 0.040 S-00237 110 S-01116 50 6.35 λ/10 5/3 x 0.040 S-00248 125 S-00980 50 9.5 λ/10 5/3 x 0.040 S-00021 150 S-00981 50 12.5 λ/10 5/3 x 0.040 S-00928 175 S-00982 60 9.5 λ/10 5/3 x 0.040 S-00929 250 S-00983 75 12.5 λ/10 5/3 x 0.063 S-00165 325 S-00984 80 12.5 λ/10 5/3 x 0.063 S-00930 380 S-00985 100 15 λ/10 5/3 x 0.063 S-00931 480 S-00986 λ All components with an € price are available from stock.
Other sizes and materials available on request. 98 back to Contents Substrates
Wedge Wedged windows 30’ Diam. Thickn. Wedge Flatness Surface UV-FS price IR-FS price Ø mm t mm 633 nm) imp.tol. Article-No. in € Article-No. in € 6230’ λ ( /10 5/3 x 0.040 S-00987 40 12.7 3 30’ λ/10 5/3 x 0.040 S-00481 45 12.7 6.35 30’ λ/10 5/3 x 0.040 S-00015 50 S-00992 60 25 3 30’ λ /4 5/3 x 0.040 S-00012 50 Ø t 25 6.35 30’ λ/10 5/3 x 0.040 S-00009 60 S-00254 75 38 6.35 30’ λ/10 5/3 x 0.040 S-00988 95 λ Tolerances 38 9.5 30’ /10 5/3 x 0.040 S-00989 100 Diameter Ø: + 0.0 /-0.1 mm 50 6.35 30’ λ/10 5/3 x 0.040 S-00990 135 Thickness t: ± 0.1 mm 50 9.5 30’ λ/10 5/3 x 0.040 S-00991 160 Parallelism/Wedge: ± 5 min. of arc λ All components with an price are available from stock. Chamfer: 0.1- 0.3 mm x 45° € Clear aperture: > 80% Surface imperfection tolerance: acc. to DIN ISO 10110-7 Large wedges 1°, 2°, 3° Diam. Thickn. Wedge Flatness Surface UV-FS price IR-FS price Ø mm t mm 633 nm) imp.tol. Article-No. in € Article-No. in € 25 6.35 1° λ ( /10 5/3 x 0.040 S-00031 80 25 6.35 2° λ/10 5/3 x 0.040 S-00032 80 S-01722 25 6.35 3° λ/10 5/3 x 0.040 S-01124 80 50 9.5 1° λ/10 5/3 x 0.040 S-00993 180 50 9.5 2° λ/10 5/3 x 0.040 S-00994 180 λ All components with an € price are available from stock.
Elliptical windows 45° Elliptical windows, used as bending mirrors, Elliptical windows can be easily mounted in deviate a beam at 90° and have an optimum protection tubes. They are polished on both cross section for circular beams. They are ideal sides and can also be used as beam splitter Ø for folded optical systems where dimensions substrates. or weight must be minimized.
Diam. Thickness Flatness Surface UV-FS price Ø mm t mm 633 nm) imp.tol. Article-No. in € λ ( 10 3 /10 5/3 x 0.025 S-01049 λ 12.7 5 /10 5/3 x 0.025 S-01050 60 t λ Wedge < 5 min. of arc 15 3 /10 5/3 x 0.025 S-01051 λ 25 3 /4 5/3 x 0.025 S-01052 80 Tolerances λ Diameter Ø: + 0.0/-0.1 mm 30 3 /4 5/3 x 0.025 S-01053 λ Thickness t: ± 0.1 mm 38 5 /10 5/3 x 0.025 S-01054 110 Parallelism/Wedge: < 5 min. of arc λ 50 5 /10 5/3 x 0.040 S-00311 190 Chamfer: 0.1- 0.3 mm x 45° λ Clear aperture: > 80% 75 8 /10 5/3 x 0.063 S-00410 350 λ Surface imperfection tolerance: All components with an € price are available from stock. acc. to DIN ISO 10110-7 99 Stock substrates
Rectangular windows Length Width Thickness Flatness Surface UV-FS price a mm b mm t mm 633 nm) imp.tol. Article-No. in € λ ( 25 15 1.5 /4 5/3 x 0.040 S-01019 60 b 25 15 3 λ/4 5/3 x 0.040 S-01020 65 30 20 3 λ/4 5/3 x 0.040 S-01021 35 25 3 λ/4 5/3 x 0.040 S-01022 80 λ 45 30 5 /10 5/3 x 0.040 S-01023 a t 50 27 1.5 λ /4 5/3 x 0.040 S-00016 50 50 27 3 λ/4 5/3 x 0.040 S-00171 90 λ 60 35 2 /4 5/3 x 0.040 S-00017 * 65 Tolerances 60 35 4 λ/4 5/3 x 0.040 S-00309 130 Length / width: + 0.0/-0.1 mm (a < 105 mm) λ 60 35 5 /10 5/3 x 0.040 S-00867 140 + 0.0/-0.2 mm (a≥ 105 mm) 75 50 5 λ /4 5/3 x 0.040 S-00415 200 Thickness t: ± 0.1 mm (t <8mm) ± 0.2 mm (t 8 mm) 105 75 8 λ/4 5/3 x 0.063 S-01024 ≥ *+ 0.0/-0.2 mm for S-00017 120 80 8 λ/4 5/3 x 0.063 S-00412 520 λ Parallelism/Wedge: < 5 min. of arc 150 100 8 /4 5/3 x 0.063 S-01025 Chamfer: 0.1-0.3 mm x 45° (a < 105 mm) λ 0.4-0.6 mm x 45° (a 105 mm) All components with an € price are available from stock. ≥ Clear aperture: > 80% Surface imperfection tolerance: acc. to DIN ISO 10110-7
Square windows
Length Width Thickness Flatness Surface UV-FS price a mm a mm t mm 633 nm) imp.tol. Article-No. in € a 10 10 2 λ( /10 5/3 x 0.025 S-00798 50 12.7 12.7 3 λ/10 5/3 x 0.025 S-00173 60 20 20 6 λ/10 5/3 x 0.025 S-01035 70 25.4 25.4 6.35 λ/10 5/3 x 0.025 S-00859 80 a t 50 50 5 λ /4 5/3 x 0.040 S-01036 All components with an price are available fromλ stock. € Tolerances Length / width: + 0.0/-0.1 mm Thickness t: ± 0.1 mm Parallelism/Wedge: < 5 min. of arc Chamfer: 0.1- 0.3 mm x 45° Clear aperture: > 80% Surface imperfection tolerance: acc. to DIN ISO 10110-7
Other sizes and materials available on request. 100 back to Contents Substrates
Plano-concave substrates UV-FS UV-FS Radius Ø 12.7 x 6.35 mm price Ø 25 x 6.35 mm price Article-No. in € Article-No. in € -10 mm S-00126 100 – 6.35 mm -15 mm S-00127 90 – -18 mm S-01061 90 – Ø -20 mm S-00807 80 – 12.7 mm -25 mm S-00128 80 S-00069 120 -30 mm S-00513 80 S-01078 110 -38 mm S-00554 70 S-01079 110 -50 mm S-00129 70 S-00070 100 -75 mm S-00130 70 S-00207 90 -100 mm S-00131 70 S-00071 80 -150 mm S-00132 60 S-00044 80 -200 mm S-00133 60 S-00072 80 6.35 mm -250 mm S-00134 60 S-00073 80 -300 mm S-00135 60 S-00074 80 Ø 25.0 mm -350 mm S-01062 60 S-00075 80 -400 mm S-00136 60 S-00076 80 -500 mm S-00137 60 S-00077 80 -600 mm S-00864 60 S-00041 80 -750 mm S-00138 60 S-00061 80 -1 m S-00139 60 S-00062 80 -1.5 m S-00140 60 S-00063 80 Tolerances Diameter Ø: + 0.0/-0.1 mm -2 m S-00141 60 S-00065 80 Thickness t: ± 0.1 mm -3 m S-00142 60 S-00064 80 Radius of curvature: ±1% -4 m S-01063 60 S-00066 80 Centering/Wedge: < 5 min. of arc -5 m S-00143 60 S-00067 80 Chamfer: 0.1- 0.3 mm x 45° -6 m S-01064 60 S-00509 80 Clear aperture: > 80% Surface imperfection tolerance: -10 m S-00144 60 S-00068 80 5/3 x 0.025 -15 m S-01065 60 S-01080 80 -20 m S-00860 60 S-00745 80
All components with an € price are available from stock.
Our plano-concave substrates are polished on both sides and can be used …
... in transmission as diverging lenses ... with a reflecting coating as focussing mirrors with the focal length with the focal length r r ft = ——–– 2r fr = — (n-1) ≈ 2
Plano-concave lens Plano-concave reflector
r r
HR AR AR f t f r 101 Stock substrates
Plano-convex substrates UV-FS UV-FS Radius Ø 12.7 x 6.35 mm price Ø 25 x 6.35 mm price Article-No. in € Article-No. in € +25 mm S-01142 100 – +30 mm S-01282 100 – 6.35 mm +38 mm S-01283 90 – Ø +50 mm S-01041 80 S-00791 110 12.7 mm +75 mm S-01284 70 S-00078 100 +100 mm S-01285 60 S-00079 90 +150 mm S-01127 60 S-01304 90 +200 mm S-01286 60 S-00080 90 +250 mm S-00551 60 S-00391 90 +300 mm S-00267 60 S-01305 90 +350 mm S-01287 60 S-01306 90 +500 mm S-00266 60 S-00081 90 6.35 mm +750 mm S-01288 60 S-00452 90 +1 m S-00552 60 S-00453 90 Ø 25.0 mm +1.5 m S-01289 60 S-00826 90 +2 m S-00553 60 S-00373 90 +3 m S-01290 60 S-00315 90 +4 m S-01291 60 S-01307 90 Tolerances +5 m S-01292 60 S-01055 90 Diameter Ø: + 0.0/-0.1 mm Thickness t: ± 0.1 mm +10 m S-01293 60 S-01308 90 Radius of curvature: ±1% All components with an € price are available from stock. Centering/Wedge: < 5 min. of arc Chamfer: 0.1- 0.3 mm x 45° Clear aperture: > 80% Surface imperfection tolerance: 5/3 x 0.025
Our plano-convex substrates are polished on both sides and can be used …
... with a reflecting coating on the convex side ... in transmission as focussing lenses with the as diverging mirrors with the focal length focal length r r fr = — ft = ——–– 2r 2 (n-1) ≈
Plano-convex reflector Plano-convex lens
r r
AR
HR f r AR f t
Other sizes and materials available on request. 102 back to Contents Substrates
Zero lenses Zero lenses have a convex and a concave side With additional plano-convex lenses, the trans- with the same radius of curvature: r =r1 = –r2. mitted and reflected beam can be focussed to The transmitted beam has the very long focal the same point similar to cavity lenses. length: 6r2 ft —–— ≈ t
t t UV-FS UV-FS Ø Ø Radius Ø 12.7 x 6.35 mm price Ø 25 x 6.35 mm price 12.7 mm 25.0 mm r1 = –r2 Article-No. in € Article-No. in € 30 mm S-00304 130 – 38 mm S-01083 120 – Tolerances 50 mm S-00597 115 S-01088 190 Diameter Ø: + 0.0/-0.1 mm 75 mm S-00598 110 S-01089 175 Thickness t: ± 0.1 mm 100 mm S-00599 105 S-01090 165 Radius of curvature: ±1% 150 mm S-00337 100 S-00497 160 Centering/Wedge: < 5 min. of arc 200 mm S-01084 100 S-01091 155 Chamfer: 0.1- 0.3 mm x 45° 250 mm S-00263 100 S-01092 150 Clear aperture: > 80% Surface imperfection tolerance: 300 mm S-00276 100 S-00493 150 5/3 x 0.025 350 mm S-00262 100 S-00256 150 500 mm S-00261 110 S-00257 150 750 mm S-00260 110 S-00259 150 1.5 m S-01085 120 S-01093 160 2 m S-01086 120 S-01094 160 5 m S-01087 120 S-01095 160
All components with an € price are available from stock.
Cavity lenses Cavity lenses are positive meniscus lenses, de- UV-FS signed for collinear pumping. Back focal length Radius Ø 12.7 x 6.35 mm price (BFL) is equal to the second radius of curvature: r2 = BFL Article-No. in € . 18 mm S-01333 260 r1 n tc BFL = r2 = —–— –tc 25 mm S-01601 240 n –1 38 mm S-01602 220 Ø Cavity lenses are optically designed for 514 nm, 50 mm S-01334 210 12.7 mm but can be used in the range 200-2500 nm with- 75 mm S-01603 200 Tolerances out significant differences. 100 mm S-01604 190 Diameter Ø: + 0.0/-0.1 mm 150 mm S-01605 190 Thickness t: ± 0.1 mm 200 mm S-01606 180 Radius of curvature: ±1% 250 mm S-01607 180 Centering/Wedge: < 5 min. of arc 350 mm S-01608 170 Chamfer: 0.1- 0.3 mm x 45° Clear aperture: > 80% 500 mm S-01609 170 Surface imperfection tolerance: All components with an € price are available from stock. 5/3 x 0.025 Cavity lens r 1 r 2
Dichroic coating
tc BFL 103 Stock substrates
Cylindrical lenses r r We offer a large range of cylindrical lenses and These can be produced in economically ad- achromates with diverse surfaces, e.g. equate lot quantities on customer demand • plane/bi-convex, in all common Fused Silica, CaF2, MgF2 and D • plane/bi-concave, other optical glasses. • toric and crossed (anamorphotic) types. L W d
r r
D
Beam L W d
Cylindrical lens
Prisms
LASEROPTIK offers a broad variety of prisms Dielectric beam splitter coatings, high reflection and prism cubes on customer demand in eco- systems and antireflection layers as well as nomically adequate lot quantities and all com- metallic layers are available upon your request. mon Fused Silica, CaF2, MgF2 and other opti- cal glasses.
Beam Rhombic prism Right angle prism Prism cube cemented or optically contacted
= HR = AR
Penta prism Dove prism Right angle prism Dove prism (inverts the Image by 180°)
Other sizes and materials available on request. 104 back to Contents Substrates
Plane-parallels, wedge < 10’’
Ø t Diameter Thickness Wedge Flatness Surface UV-FS price Ø mm t mm Parallelism 633 nm) imp.tol. Article-No. in € Tolerances 25 6.35 <10’’ λ ( /10 5/3 x 0.040 S-01015 90 Diameter Ø: + 0.0/-0.1 mm λ Thickness t: ± 0.1 mm 50 9.5 <10’’ /10 5/3 x 0.040 S-01016 160 Chamfer: 0.1- 0.3 mm x 45° λ All components with an € price are available from stock. Clear aperture: > 80% Surface imperfection tolerance: acc. to DIN ISO 10110-7
Etalons, wedge < 0.2’’ Fabry-Perot etalons are extremely narrow line The final finesse of the etalon is in most cases width filters with a series of sharp transmis - limited by the flatness finesse F F (flatness of sion peaks, separated by the free spectral /20 gives F F = 20) for beam diameter 20 mm. λ range (FSR). FSR depends only on the optical With thinner beams F F can grow to > 200. Pairs thickness of the etalons, whereas the finesse of etalons in series may be used to obtain ultra (F) is determined not only by the reflectivity of high resolution combined with a very long FSR. the coatings, but mainly by surface quality, The resulting finesse of such a combination parallelism, homogeneity of the substrate ma - can be one order of magnitude higher. Ø t terial and defect-free coatings. Solid etalons 25.0 mm can be tuned by tilting and by temperature Besides lower costs, solid etalons offer the fol - Tolerances change. lowing advantages over air spaced etalons for Diameter Ø: + 0.0/-0.1 mm intracavity use: Thickness t: ± 20% (< 0.3 mm) If a minimum resolvable resolution is nee - • higher transmission ± 5% ( ≥ 0.3 mm) ded, the reflectivity finesse F can bΔe λ calcula - • lower size ± 0.1mm ( 2mm) R ≥ ted with • harder coatings with Chamfer: 0.1- 0.3 mm x 45° — (for t > 0.5 mm) FSR π√R • higher damage threshold FR = ——— = ———— Clear aperture: Ø 20 mm 1–R Surface imperfection tolerance: Δλ acc. to DIN ISO 10110-7 18 200
FR FR — π√R FR = ––––– 14 140 1–R 12 120 10 100 8 80 6 60 4 40 2 20 0 0 20 40 60R (%) 80 80 82 84 86 88 90 92 94R (%) 100
Please specify thick ness, cen - Diam. Thickn. Wedge Flatness in T Surface Suprasil 311 price FSR FSR ter wavelength and reflectivity Ø mm t mm Parallelism 633 nm) imp.tol. Article-No. in € nm @ 633 nm GHz in your order. 25 0.1 <0 .2’’ λ ( /20 5/3 x 0.040 S-00209 210 1.38 1000 25 0.2 <0 .2’’ λ/20 5/3 x 0.040 S-00185 200 0.69 500 Please contact LASEROPTIK to 25 0.3 <0 .2’’ λ/20 5/3 x 0.040 S-00740 200 0.46 330 discuss your specific require - 25 0.5 <0 .2’’ λ/20 5/3 x 0.040 S-00353 190 0.28 200 ments. 25 1 <0 .2’’ λ/20 5/3 x 0.040 S-01001 180 0.14 100 25 2 <0 .2’’ λ/20 5/3 x 0.040 S-00932 170 0.069 50 25 3 <0 .2’’ λ/20 5/3 x 0.040 S-00933 170 0.046 33 25 4 <0 .2’’ λ/20 5/3 x 0.040 S-00029 170 0.034 25 25 5 <0 .2’’ λ/20 5/3 x 0.040 S-00206 180 0.028 20 25 6.35 <0 .2’’ λ/20 5/3 x 0.040 S-00934 190 0.022 16 25 10 <0 .2’’ λ/20 5/3 x 0.040 S-00754 200 0.014 10 25 20 <0 .2’’ λ/20 5/3 x 0.040 S-00495 300 0.007 5 λ All components with an € price are available from stock. 105 Stock substrates
CaF2 substrates Length Width Thickness Surface 157 nm price 193 nm price 248 nm price VIS/IR price a mm b mm t mm imp. tol. Article-No. in € Article-No. in € Article-No. in € Article-No. in € 50 27 2 5/3 x 0.040 S-00728 480 S-00195 400 S-01636 300 S-00333 210 60 35 2 5/3 x 0.040 S-00562 690 S-00194 490 S-01637 440 S-00334 360
Diameter Thickness Surface 157 nm price 193 nm price 248 nm price VIS/IR price Ø mm t mm imp. tol. Article-No. in € Article-No. in € Article-No. in € Article-No. in € 12.7 3 5/3 x 0.063 S-01638 100 S-00653 95 S-01639 90 S-01640 85 25 6.35 5/3 x 0.063 S-00374 360 S-00748 340 S-01641 300 S-00169 190 38 6.35 5/3 x 0.063 S-01642 470 S-01643 380 S-01644 360 S-00753 300 50 9.5 5/3 x 0.10 S-01645 980 S-01221 800 S-01646 750 S-01647 630 All components with an € price are available from stock. Transmission diagram of CaF2 substrates see page 91. Tolerances CaF2 Length/Width: + 0.0/-0.1 mm Thickness t: ± 0.1 mm Parallelism/Wedge: < 5 min. of arc Chamfer: 0.1-0.3 mm x 45° (for t > 0.5 mm) Clear aperture: > 80% Flatn. round substr.: /4 Flatn. rectang. substr.: λ/2 Surface imperfection tolerance:λ acc. to DIN ISO 10110-7
MgF2 substrates ZnSe substrates Diam. Thickn. Flatness Surface VUV-MgF2 price Diam. Thickn. Flatness Surface ZnSe price Ø mm t mm 633 nm) imp.tol. Article-No. in € Ø mm t mm (633 nm) imp.tol. Article-No. in € 12.7 3 λ ( /10 5/3 x 0.063 S-01648 180 25.4 3 λ /4 5/3 x 0.063 S-00271 200 25 6.35 λ/10 5/3 x 0.063 S-00046 260 25.4 6.35 λ/4 5/3 x 0.063 S-01692 250 38 6.35 λ/10 5/3 x 0.063 S-01649 490 38.1 5 λ/4 5/3 x 0.063 S-01693 330 50 9.5 λ/10 5/3 x 0.10 S-01650 940 50.8 6.35 λ/4 5/3 x 0.10 S-00387 500 λ λ All components with an € price are available from stock. All components with an € price are available from stock. Transmission diagram of MgF2 substrates see page 91. Transmission diagram of ZnSe substrates see page 92.
Sapphire substrates Undoped YAG substrates Diam. Thickn. Flatness Surface Sapphire price Diam. Thickn. Flatness Surface undoped YAG price Ø mm t mm 633 nm) imp.tol. Article-No. in € Ø mm t mm (633 nm) imp.tol. Article-No. in € 12.7 3 λ ( /10 5/3 x 0.063 S-00469 95 12.7 3 λ /10 5/3 x 0.063 S-01479 100 25.4 3 λ/4 5/3 x 0.063 S-01630 170 25.4 3 λ /4 5/3 x 0.063 S-00876 250 λ λ All components with an € price are available from stock. All components with an € price are available from stock. Transmission diagram of Sapphire substrates see page 90. Transmission diagram of YAG substrates see page 90.
Tolerances MgF2, ZnSe, Sapphire, undoped YAG Diameter: + 0.0/-0.1 mm Thickness t: ± 0.1 mm Parallelism/Wedge: < 5 min. of arc Chamfer: 0.1-0.3 mm x 45° Clear aperture: > 80% Surface imperfection tolerance: acc. to DIN ISO 10110-7
Other sizes and materials available on request. back to Contents 107
About us
Production flow Substrate cleaning Measuring methods History Appendix 108 back to Contents About us
Production flow
Ordering from stock
Inquiry and quotation Order scheduling Pre-production Substrates cleaning before ordering after ordering between ordering and immediately before coating coating
Customer gets into contact Print process control quality Check availability of Clean substrates page 110 with our experts plan for every order
• by phone, fax, email • guides the order to every • substrates and holders • 100% inspection under cover III production step stereo microscope • coating materials • by LOOP (LASEROPTIK • includes all nessecary in- Online Portal) page 5 formation
+ choose or calculate design + schedule runs on coating + fit machine parameters to + substrates can be supplied according to custo mer's machine coating design by LASEROPTIK and/or by needs page 21 customer page 96 + commission substrates + check if customer-owned + choose suitable substrates substrates will arrive two page 86 + commission substrate weeks before coating date holders + need faster turnaround, use LASEROPTIK EXPRESS? page 4
-> send quotation including -> send formal order confir - -> re-schedule if customer- -> if customer owned substra - computed curve mation owned substrates are de- tes have unusual defects,we layed ask for exceptional approval 109 Production flow
Coating process Measurement Final inspection Shipping after coating before shipping
Different coating techniques Normallywitness samples are 100% inspection under Working with all standard are available page 20 used for measurements stereo microscope delivery services
• thickness measurement • to avoid damaging of the • special inspections after • best on customer's interna- optically and/or physically substrates customer’s specification tional account number are possible • post coating treatment • samples have similar re- • faster shipment can be ar - fractive index and matching ranged at additional costs size for the measurement setup
+ takes up to 1.5 hours for + standard measurement by + dust-free packaging in flow- + extra soft wrap for a secure reaching temperature and spectrometer box / cleanroom transport high vacuum + more measurement tools + every optic is marked di- + including invoice and + coating time varies from are available page 112 rectly or on its packaging measured curves 5 min. (single AR) to over 36 hours (IBS filters)
LASEROPTIK is ISO:9001-certified since 1998 110 back to Contents About us
Substrate cleaning
The quality of the coatings is a critical point in If substrates are not suited for automatic clea - the production of high power laser compo- ning (for example hygroscopic material), they nents. And that quality starts with the cleaning are manually cleaned under laminar flow condi- of the substrates before coating, to eliminate tions. This process is similar to the one descri - all possible contamination. bed on the next page, "Cleaning of coated op- tics". At LASEROPTIK all suitable substrates are auto- matically cleaned in one of three available mul - Both, substrate cleaning and coatings are per- ti chamber ultrasonic cleaning lines. formed in well maintained cleanrooms. In any case cleaned substrates are inspected for 100% A robot system moves the substrates automati- under a stereomicroscope before mounting them cally, fol lowing identical process steps. The to- into the substrate holders and fixing them in the tal process takes 30 to 50 minutes. coating machine immediately afterwards.
Cleaning line process
C1 R1 C2 R2 PWR LO IR
1. 2. 3. 4. 5. 6. Cleaning with The cleaning Repeat step 1. Repeat step 2. Pure water rinse Lift-out, Final drying by ul trasonic (gener- goods are rinsed with DI water (de- slowly lifting out IR-radiation. ators for 40/80 with reverse ionized), produ - of the DI water to kHz). osmosis (RO) ced in circulating guarantee resi due- Power and dura- water. systems. free drying. tion are varied due to the needs of the material to clean and its con- dition. Used detergents are alkalescent. 111 Substrate cleaning
Cleaning of coated optics
We recommend to clean coated optics with clean air only. If the surface is very dirty you can try the following steps:
1) Blow off the optic with clean air or nitrogen to remo ve particles.
2) Fold cleaning tissue (like lens cleaning tissue Whatman 105) or microfiber cloth (Toraysee MK14.5H) into a suit- able form according to the size of the surface to be clea - ned.
3) Moisten the tissue or cloth with recommended solvents like isopropanol or ethanol.
4) Clean the coated surface with uniform circular move - ments and low pressure. Coated optics produced by IAD, IP, MS and IBS can normally resist some more pres- sure.
5) The removal of the tissue or cloth from the coated sur- face should be straight and without any pressure.
6) Check the cleaning results with a bright light source and/or under a microscope.
Ultrasonic cleaning line for substrates in clean- 7) Repeat the cleaning processes if the optic is still dirty. room environment Please notice the following:
• To avoid fingerprints use powder free clean gloves (la- tex, nitrile). • If you use tweezers to hold the substrate use tweezers with protected tips (e.g. rubber or cork). • When cleaning small optics hold the folded tissue or cloth with clamp tweezers. • Change the tissue or cloth as often as possible.
This cleaning recommendation refers to optics which are coated with metal oxide layers and / or with a protec- tive layer.
For more information about cleaning of coated optics please contact us. We can assist you even on the phone.
Cleaning manually 112 back to Contents About us
Measuring methods for laser optics
LASEROPTIK has more than 30 years experien- ce with high quality coatings. In these years we were able to collect valuable knowledge about the properties of our optics from the best labo- ratories we could find: the experiences and feed backs of our customers.
Additionally we developed new coating techni - ques, measurement devices and improved coa- ting materials in co-operation with research partners like Laser Zentrum Hannover e.V. (LZH), Fraunhofer Institute for Applied Optics and Pre- cision Engineering (IOF) in Jena or Laser-Labo - ra torium Göttingen e.V. (LLG).
To guarantee stable high quality of our optics LASEROPTIK owns a wide range of measuring equipment which is presented on the following pages.
Focal length and wedge Optical standard parameters like effective focal length (EFL), back focal length (BFL), radius of curvature, modulation transfer function (MTF) or centring errors are inspected using an Opti- Spheric®. Radii of 5 mm up to 500 mm and centering errors in the ran ge of 10” to 5’ can be detected. Additionally it is possible to measure wedges from 10” to 1.5°.
Optical surface inspection Uncoated and coated optics are inspected with standard OLYMPUS microscopes or ZEISS differential interference contrast microscopes and for larger surfaces with a Keyence flexible microscope.
Flatness To inspect the accuracy of the surface we use a Twyman-Green interferometer with a measuring wavelength of 632.8 nm. It can work with a maximum aperture of 4" and a flatness down to /20 at room temperature. The flatness can be λmeasured in transmission and reflection re- Surface roughness ferring to ISO 10110. For the production of low loss components it is necessary to quantify the surface roughness. Thin film stress This rms-value is measured by a whitelight- For many applications it is important to know inter ferometer which is combined with a micro- exactly the thin film stress, respectively to scope. The measuring sensitivity goes below compensate for the bending of the optics due 0.1 nm rms. to this stress. LASEROPTIK uses an in-situ stress 113 Measuring methods
measurement system and interferometric mea- surements for the quantification of the induced stress.
Group delay (GD) and group delay dispersion (GDD) For fs-optics the control of the phase respecti - ve ly the group delay and group delay disper- sion of the coatings is of great importance. Be- sides a custom built one LASEROPTIK uses a white light interferometer from KMLabs (Chro- matis). The measurements can be done in the Reflectance and transmittance wavelength range 600-1650 nm, an angle of The most important quality tool in optical thin inciden ce 0-60° and with both polarizations at film production is the spectrophotometer. the same time. It is possible to measure single LASEROPTIK uses different types to measure mirrors as well as mirror pairs. transmittance respectively reflectance from va - cuum-UV (120 nm) to infrared up to 50 µm. Environmental testing Besides a VUV-spectrometer built by LZH we A climate chamber and other equipment for en - mainly use PERKIN-ELMER spectrometers vironmental testing enable us to deliver optics (Lambda 19/883/900/950/1050/ Frontier Op- fully certified for customer applications accord- tica). To give the coating engineers always a ing to MIL and ISO standards. prompt access to a spectrometer for getting a fast feedback on the actual production pro ces - Scattering ses we provide one spectrometer for every two Forward and backward scattering can be de- coating machines. tec ted in the wavelength range 190-800 nm by a self-constructed measuring device with a Climate chamber and abration- Coblentz sphere. Additional external qualifi - test-set for environmental testing cations can be done by IOF or LZH.
Absorption and laser induced damage threshold (LIDT) LASEROPTIK has a long-standing cooperation with the LZH for the characterisation of optical coatings. The most important measurements are laser damage threshold (LIDT according to ISO 21254), optical losses, i.e. absorptance (ISO 11551) and scattering (ISO 13696). Espe- cially the LIDT has gained increasing impor- tance for optical components. Cavity ring-down (CRD) The accuracy of reflectance measurements with spectrophotometers is limited. Therefore To produce high power optics you have to con- a cavity ring-down setup is employed to measu - sider the different mechanisms of laser indu - re high reflectance at least for the wavelengths ced damages and the influences of the substra - 635 nm and 1064 nm. tes and coating materials. Therefore we would By analyzing the power decay in the cavity re- like to provide some background information in flectance can be measured in a range from the following pages. 99.5% to 99.999%. Typical application exam- ples for cavity ring-down measurement are low loss mirrors. 114 back to Contents About us
Laser Induced Damage Threshold (LIDT)
The Laser Induced Damage Threshold (LIDT) of mi nation of layers from the surface of the opti- optical components is a critical quality parame- cal component in the center of the laser beam ter for laser systems and their applications op- area (s. Fig. 3). erated at high power levels. Historically optical materials could be optimized to excellent quali- These damaging effects are results of instanta - ty as well as power handling capability, and ne ous heating of the coating material in the consequently, the problem of laser indu ced area of interaction with the laser beam. This damage shifted from the bulk to the surface of can be modeled on the basis of adapted heat the optical component during the last decades. diffusion equations and corresponding boun- dary conditions. For the temperature rise ( T) During production the optical surface is object- in the center of an irradiated circular compo-Δ Figure 1: Absorption induced ed to various influences, which modify its struc- nent and a Gaus sian beam profile with power melting ture and composition. However the thin film (P) a first order expression can be derived: coating system, which is deposited onto the op- Equitation (1) tical surface to adapt its reflectance and trans- mittance to the application, contribu tes pre- 1⁄2 2 sP 16κtI dominantly to the reduction of the LIDT-values. β tan–1 ( ) ΔT ______3⁄2 kw______w2 It is considered the most critical element in the = π development of high power laser components. Obviously, the temperature rise is dependent The following contains a short overview of some on the thermal properties (k: thermal conduc- major aspects of laser damage in optics includ- tivity, κ: thermal diffusivity), on the surface ab- ing a summary of the observed damage mecha- sorption of the component ( s), and on the nisms in thin films, an introduction into LIDT beam diameter (w). β measurements according to the recent ISO- Stan dard series, and a few remarks concerning For long irradiation times tI compared to the ty - 2 Figure 2: Absorption induced scaling of LIDT values. pical heat diffusion time w /κ equation (1) can recrystallization be reduced to the following asymptotic approx- Laser damage mechanisms imation: Equitation (2) Laser damage in optical coatings may be initiat- sP ed and driven by a variety of interactions of mat- β ΔT ______1⁄ 2 ter with radiation. In many cases optical absorp- → kw tI→∞ tion processes couple thermal energy into the π coating structure under irradiation and cause a This asymptotic behavior applies to long irradi- sharp increa se of temperature until a catastro - ation times or cw-operation of the laser. In con- phic failure by mechanical disruption or over- trast to this, the short pulse regime is represen - heating occurs. A typical damage site attribu ted ted by the first equation. to such an absorption induced coating failure is depicted in Figure 1. For damages dominated by absorption the follo wing can be stated: In this example the laser induced temperature • short pulses: LIDT ~ power density P/w2 Figure 3: Absorption induced rise was sufficient to reach the melting point of • long irradiation times or cw: LIDT ~ linear stress the material leading to an evaporation of coat- power density P/w ing material and a change in its crystalline In practice absorption induced damage of laser structure. If laser power densities slightly ex- components is occasionally observed in coating ceed the damage threshold of the material, you materials for the DUV/VUV-wavelengths and in often can observe discoloration or increased the MIR-range. surface roughness in the center of the laser beam and no removal of material. (s. Fig. 2). For the VIS- and NIR-spectral range modern opti- cal coating production processes have been de- Thermal ex pan sion driven by laser indu ced veloped resulting in extremely small absorption heating may also result in a mechanical stress losses. For these layer systems laser damage is level exceeding the adhesion strength of the dominated by defects which are embedded in coating to the substrate. Corresponding typical the layer structure and which possess a signifi- damage morpho lo gies clearly indicate a dela - cantly higher absorption than the surrounding 115 Measuring methods
layer material. Under laser irradiation, these de, theoretical models describing damage in absorbing defects heat up much faster than the the ultrashort pulse regime have been devel - surrounding material and explo de removing the oped to a state which allows the forecast of the covering layer structure. A typical damage site of damage beha vior as a function of the ele ctro - such a defect or inclusion dominated da mage is nic properties of the involved dielectrics. In characterized by small craters in the beam area many practical applications a variety of ad ditio- (s. Fig. 5) . nal influences may also impair the power han - dling capability of a laser component. Since the specific optical, thermal and geome - tric properties of the defects are usually not Weak points are improper handling and clean - known in detail, a theoretical description of de - ing as well as contamination of the coated sur - fect induced damage can only provide trends in faces. Under special environmental conditions, Figure 4: Helix nebula, infrared, the scaling of damage with laser parameters the laser radiation may even induce the growth Spitzer Space Telescope, NASA and the material properties. Precise modelling of contamination on the optics via transporta - is even more complicated by the statistical dis - tion effects or photochemical reactions and ini - tribution of defects in size and physical proper - tiate laser damage by increased surface ab - ties demanding for defect characterization tech - sorption . Voids, grooves, pores, or scratches on ni ques with extremely high sensitivity down to the optical surface also reduce the damage the nm-scale on the experimental side. threshold of the optical element, because they act as concentrators for the electric field. Defect induced breakdown is the type of da - ma ge predominantly observed for most laser To avoid laser induced damages: ope ra tion regimes. It is still a topic of intensiv • Use the right substrates with low absorption, research in laser da mage as well as in the de - low water content and good polishing if ne - ve lop ment of deposition processes with redu- ces sary. ced defect gene ration. • LASEROPTIK uses the best fitting coating ma - terials and coating techniques (low absorp - Figure 5: Defect induced damage Besides thermal effects, direct electronic excita - tion, low defects and best electronic proper - tion may be considered as driving mecha nis m ties) for your applications. And we produce for short pulse laser damage. These types of di - under cleanroom conditions. electric breakdown mechanisms mo ved into the • Handle coated optics with care and in appro - focus of research after ultra-short pul se lasers priate environmental conditions. with high output power could be develo ped. The excitation of electrons into the conduction Measurement of LIDT-values band of a dielectric material by multiphoton processes becomes more probable at the ex - After long technical discussion, extending over tremely high power densities of pulses with du - more than ten years, the standard series ISO rations in the ps- and fs-range. These electrons 11254 for the measurement of LIDT-values had can contribute to a further increase of the free been published in the time period from 2000 electron density in the conduction band via a to 2006. In view of new developments in laser stepwise excitation to higher energy le vels and technology this standard was revised and is a subsequent relaxation with energy transfer to now published as a new series, ISO 21254 . a valence band electron to perform a transition Besides the measurement protocols and data to the conduction band (Avalanche effect). evaluation procedures for damage testing with single pulse and multiple pulses described in In this model, damage occurs at a critical elec - the first three parts, this revised standard se - tron density in the conduction band in the ran - ries also contains an ISO Technical Report on ge of a few 10 21 1/cm 3. After reaching this sta - damage detection in modern measurement te, laser radiation is instantly coupled into the facilities. The basic ar ran gement of a damage free electron plasma leading to catastrophic test facility according to ISO 21254 is illustrated damage of the material. During the last deca - in Figure 6 .
Figure 6: Fundamental setup for Sample Imaging Attenuator Laser the measurement of laser induced chamber system system system damage thresholds. Damage detection Beam diagnostics 116 back to Contents About us
1.0
0.8 Test data 0.6 Ramp fit Damage frequ.
Operating as the central element in transversal Damage probability and longitudinal single mode, the test laser 0.4 source is used with its beam parameters pre- cisely monitored by a beam diagnostic system. 0.2 The spatial and temporal profile as well as the energy of the laser radiation in the target plane 0 0 50 100 150 200 250 are recorded with the diagnostic system and Energy density [J/cm2] evaluated in respect to the error budget of the measurement. Figure 7: Survival curve 1 on 1 damage test
To induce damage of a component an optical interest and of limited importance for practical imaging system concentrates the laser radiation applications they are still listed in many cata- on a sample surface within a well-defined spot logues of optics manufacturers. A more realistic of sufficiently high energy density. To tune the scenario is simulated in S on 1-tests involving laser fluence in the target plane an adjustable an extended irradiation of the sample with a se- attenuator is installed between the laser source ries of pulses. The test is performed similar to and the imaging device. A positioning system the 1 on 1-protocol with the exception that each moves the test sites on the sample surface into test site is exposed to a train of a defined num- the test beam. Normally this process is con- ber S of identical pulses of preselected laser flu- trolled by a computer that, in modern laser dam- ence. In this test procedure damage can actual- age facilities, at the same time also controls the ly occur before delivery of the complete train of complete measurement procedure. pulses to a site.
In the classical so-called 1 on 1-testing proce- As a consequence, the test facility has to be dure, each test site is exposed only one time to equipped with an online damage detection sys- a single laser pulse. The complete 1 on 1-mea- tem which ceases the laser irradiation and surement protocol consists of multiple irradia- records the number of pulses N until damage tion cycles with pulses of different energies, occurred. The generated data is evaluated by covering specific low fluence values without da - deriving survival curves for preselected num- mage and high values always causing da ma ge. bers of pulses providing the so-called character- istic damage curve as the final result of the test. After the irradiation sequence, the specimen is An example for such a plot of the energy density inspected in respect to the damage sta te of the values for selected damage probabilities as a individual sites by Nomarski inter fe rence con- function of the number of pulses is depicted in trast microscopy, which is the standard routine Figure 8. according to ISO 21254, or any other highly re- solving surface measurement technique with An interesting practical aspect is the extrapola- similar sensitivity. The resulting raw data of the tion of the characteristic damage curve to high test routine comprises of a set of fluence values pulse numbers in the order of 109 to 1012 shots with assigned damage sta tes. which may allow for a rough estimation of the lifetime of test component. For the presentation of the final result, the da - mage probability as the ratio of the number of For a certification of optical components in re- damaged sites to the total number of sites ex- spect to their power handling capability, the posed is calculated for a representative series third part of ISO 21254 describes testing proto- of fluence values. Subsequently, these damage cols of a defined surface fraction at highest probability values are plotted as a function of power levels expected in the application. The fluence representing the final result of the test. fundamental approach of these tests is an over- An example for such a diagram, which is often lapping interrogation of the entire test area of called the survival curve of the optical compo- the optical component, to identify weak spots nent, is illustrated in Figure 7. on the surface and to achieve a high level of confidence for an error-free operation of the op- The damage threshold is given as the highest tic in the application. quantity of laser radiation for which the extrapo- lated probability of damage is zero. Even though Accordingly, the original component intended today 1 on 1-thresholds are mainly of academic for direct use is probed in the certification pro- 117 Measuring methods ] 2 120 0% LIDT 100 50 % LIDT First observed damage 80 cedure instead of representative samples, 60 which are tested in 1 on 1- or S on 1-test proto- J/cm Energy density [ cols. LIDT is measured at the facilities of our 40 partner Laser Zentrum Hannover e.V. (LZH). 20
0 1 10 100 1000 Scaling of laser damage Number of pulses
For the application of laser coatings, some Figure 8: Characteristic damage curve, S on 1 rough scaling rules can be derived from the de- veloped models (see also page 17). The most cal defect will asymptotically reach unity with in- prominent estimation for the LIDT-values is the creasing beam diameter, and the LIDT will ap- square root rule for the pulse duration ( ): proach its smaller value related to defect dam- τ age. In most practical situations, the beam size LIDT ~ x ; x = 0.5. exceed the mean distance of defects by far, and τ therefore, the onset of laser induced damage Typically this can be used in the pulse duration can be estimated as virtually independent of regime between 0.1 to 10ns. The dependency the beam diameter for inclusion dominated can be extended to other pulse regimes up to breakdown. pulse lengths in the ms-range, if the exponent is replaced by figures ranging between 0.5 and As mentioned above for pure absorption indu - 2. However, this scaling applies mainly for ther- ced damage and with shorter pulse durations, mal damage processes and has to be applied approximation for the beam diameter depend- with extreme care, particularly for extrapola- ence of LIDT on the basis of P/w2 is often accep - tions spanning more than one order of magni- table (page 114). But with cw-lasers or long pul - tude in pulse duration. Especially below values ses in the µs- to ms-range, the scaling of the of 20 ps, a transition from thermal processes to threshold with the beam diameter should be the described electronic effects has to be ac- performed in terms of P/w according to equa- counted for, and the x -scaling may no longer tion 2. This P/w scaling results in lower thresh- be applicable. τ olds than the scaling with intensity, which is of- ten erroneously assumed by users, leading to For most materials and under most operating a fatal overestimation of LIDT-values in these conditions you can observe a decrease of the operation regimes, one example: LIDT value with decreasing wavelength. Scaling with wavelength always implicates the risk that A mirror shows a maximum safe power of 100 W damage mechanisms may change with wave- with a beam diameter of 0.5 mm. Using the po - length, especially when absorption bands are wer density for scaling to a beam diameter of 5 approached. Often, a delay in the range of sev- mm the safe operation power would be 10 kW. eral 10 seconds between the start of irradiation Scaling with the linear power density only 1 kW and the onset of damage has to be taken into will be safe! account for thermal pro cesses. In summary, LIDT-values of optical components Concerning the variation of LIDT-values with and thin films are crucially dependent on the beam diameter, numerous investigations indi- operation conditions of the applied laser sys- cate a decrease in thresholds for increasing tem. The mentioned change of damage effects beam diameters. Specifically for inclusion domi- from thermal to electronic mechanisms is only nated breakdown, the event of damage for a one representative example among a variety of cer tain site on the coating will be essentially de- many other observed phenomena. As a conse- pendent on the distribution of inclusions at that quence, threshold values should be scaled position. In the case of defect damage, for ex- with extreme care and for only small intervals ample, with beam sizes smaller than the mean in cases, where the fundamental damage distance between defects vulnerable to damage mechanism is clarified. In all other situations, in the coating, the probability for interrogating a the extrapolation of threshold values is extre- Recommended further reading: critical defect will be low, and the threshold will mely unreliable and may lead to severe hazards Ristau, D. : Laser-induced damage in be high depending on the quality of the coated in the laser system. optical materials, CRC Press (January 9, material. The probability of interrogating a criti- 2015), ISBN-13: 978-1439872161 118 back to Contents About us
History
1984 2006 LASEROPTIK was founded by Dr. Johannes Ebert, LASEROPTIK EXPRESS is on with involvement of his wife Angelika and to- the run, a rapid prototyping day's senior coating manager Werner Moorhoff. and over night coa ting service. In the 12 preceding years Dr. Ebert had gai ned More than 100 orders were experience in the manufacturing and character- pro cessed in the first year. isation of thin films at the Institute of Quan tum Optics at the University of Hanover. He became 2007 a pioneer in the development of plasma- and LASEROPTIK is the first professional coating ion-guns, for the reduction of absorption- and company outside the USA to offer IBS coatings. scatter-losses and for the improvement of the Due to the high demand, the capacity has in- damage resistance of high power coatings. creased to today’s 10 machines including 2 Dr. Johannes Ebert ones for large optics. 1986 As spin-off of the ”Institute of Quantum Optics“ the ”Laser Zentrum Hannover e.V. (LZH)“ is foun - ded in close vicinity (only 10 km) to LASER - OPTIK's site: The beginning of a constructive and fruitful cooperation.
1990 LASEROPTIK runs 3 Balzers coating machines, two of them in Dr. Ebert's modified basement ”Kelly“, the first IBScoatingmachine at LASEROPTIK ”Paula“, the first coating machine at home. 2008 1992 Dr. Wolfgang Ebert is taking over the general A new company building is erected and furni - management from his father. Starting work for shed with 7 additional Balzers coating machi - the company in 1997, he learned the skills of a nes over the following years. The ”Optics Barn“ thin film engineer from scratch. Since then he (”Optikscheune“) is con struc ted in the style of a has left his own foot- Lower Saxony half-timbered house and is equip - prints as head of new ped with the latest cleanroom techno logy. programs and initia- tives like the EXPRESS 1999 service, LOOP, the de- LASEROPTIK starts a two year R&D effort with velopment of IBS, in- The ”Optics Barn“, the first DSI Inc., USA. In close collaboration with the novative coating con- company building american engineering experts, Martin Ebert, cepts and various the founder's elder son, develops a unique other strategic and magnetron sputtering system and establishes pragmatic advances. this technology at LASEROPTIK. 2008 2002 LASEROPTIK proudly describes itself as a high- Under the leadership of Dr. Ebert's sons Martin tech family business. This means besides taking and Wolfgang a new company building – the care of the long term growth and continuous ”Laserhof“ – is erected. It provides additio nal reinvestments to give our customers and suppli- space for a number of coating machines in ers a reliable perspective, we take the responsi- three cleanrooms. bility for our employees very seriously. ”Gabrielle“, the unique MS-system developed by ”We need more space!“ LASEROPTIK The ”Laserhof“ was erected in 2002 inclu- ding 1000 m2 clean- room production. 119 History
2009 The Ebert family erected a nesting place on the grounds of LASEROPTIK in order to support the resettlement of the endangered white stork (lat. ciconia ciconia). The initiative was success ful, until today 14 young storks grew up.
In the natural habitats on the company's ground a lot of other protected species such as frogs, salamanders, owls and bats can be ob- served.
To save energy and environmental resources, the waste heat of the coating chambers is used The company runs its own corporate childcare for heating the laboratories and offices. with a kindergarten teacher, for the children of LASER OPTIK has a recycling and waste mana- the employees, starting at the age of 1 year. ge ment in place and is supplied by 100% eco- logical power from regenerative sources. The working culture at LASEROPTIK is also ex- pressed in company outings and annual family 2011 events such as ball rolling (”Bosseln“) across LOOP is introduced, the LASERO PTIK LOOP is the most comfortable way the fields in wintertime, summer parties and Online Portal. It allows to individual- to configure, order and buy online excursions. ly configure and buy laser optics online. The from the LASEROPTIK stock. web-based system gives access to more than 1000 different coatings, including tolerances and theoretical calculations.
2014 Due to market demand, LASEROPTIK has star- ted a second building extension of the ”Laser- hof“ with additional 3500 m2 and tailored clean rooms, e.g. for grand IBS machines.
”Bosseln“ – a cross-country enjoyment in winter In 2017 a staff of more than 80 employees and springtime. (laserphysicists, engineers, technicians, precision opticians) works on your coating needs at LASEROPTIK.
After 10 years it became necessary to expand the ”Laserhof“ to 7900 m2 to meet the strong de- mand for high power optics. 120 back to Contents About us
Appendix Abbreviations
ALD atomic layer deposition MIR middle infrared; 2.5-50 µm AOI angle of incidence MS magnetron sputtering AR anti reflection coating ARS angle resolved scatter NA numerical aperture avg average N-BK7 borosilicate crown glass NIR near infrared; 780-2500 nm BB... broadband... NP... nonpolarizing ... BFL back focal length BS beamsplitter Ø diameter BW bandwidth OAP off axis parabola OC output coupler CA clear aperture OD optical density cc concave OPO optical parametric oscillator CP cube polarizer ord. ordinary CRD cavity ring-down cw continuous wave pl plano CWL center wavelength ppm parts per million cx convex p-pol p-polarized light PR partial reflector DAR double AR PV peak to valley DR double reflector QWOT quarter wave optical thickness EAR single layer AR coating QWS quarter wave stack EBE electron beam evaporation EFL effective focal length R reflectance RF radio frequency F finesse Rp p-polarization reflectance FC fiber coupling Rs s-polarization reflectance FF flatness finesse rms root mean square FL focal length ROC radius of curvature FR reflectivity finesse fr focal length in reflection SP short (wave) pass FS Fused Silica s-pol s-polarized light FSR free spectral range ft focal length in transmission t thickness FWHM full width half maximum T transmittance tc center thickness GD group dispersion TE thermal evaporation GDD group delay dispersion TFP thin film polarizer GTI Gires-Tournois-interferometer TIR total internal reflection GVD group velocity dispersion TIS total integrated scattering Tp p-polarization transmittance HBW half bandwidth Ts s-polarization transmittance HR high reflection coating TSB total back scattering
IAD ion assisted deposition UHV ultra-high vacuum IBS ion beam sputtering u-pol unpolarized light u = (s+p)/2 IP ion plating US ultrasonic IR infrared UV ultraviolet; 180-379 nm IR-FS Fused Silica with low OH-content UV-FS Fused Silica with high UV-transmittance ISO International Standards Organization IVA inversively variable attenuator VA variable attenuator VIS visible light; 380-779 nm wavelength VLT visible light transmission LIDTλ laser induced damage threshold VUV vacuum ultraviolet; 120-179 nm LOOP LaserOptic Online Portal LP long (wave) pass 121 Appendix
Helpful formulas
n–1 2 Fresnel reflectivity: R = ——— with normal incidence in air ( n+1 )
Snell’s law: n1sin 1 = n2sin 2 θ θ
n2 Total reflection: sin T = —— ;n2 < n1 θ n1
nsubstrate Brewster’s angle: B = arctan —————— θ ( nmedium )
Numerical aperture: NA = n·sin θ OD T 4 0.01 % –1 3 0.1 % Optical density: OD = log10(T ) 2 1.0 % 1 10.0 % 2 Free spectral range: FSR = —————λ n is the refractive index of the cavity and d the cavity gap 2 . n . d — FSR . R Reflectivity finesse: F = ——— = π————√ R 1-R Δλ 104 E Wavenumber: = ———— cm–1 λ ṽ ṽ [µm] 193 nm 51813 cm–1 6.42 eV λ 355 nm 28169 cm–1 3.49 eV 1.24 532 nm 18797 cm–1 2.33 eV Electron volts: E = ———— eV –1 [µm] 1064 nm 9398 cm 1.17 eV λ 1550 nm 6452 cm–1 0.80 eV E 2940 nm 3401 cm–1 0.42 eV Planck’s constant: h = — = 6.62607 · 10–34 Js v
m Speed of light: c = 299 792 458 — in vacuum s
11_ __ LO solving equation: nnsin x = sin x = six = 6
6.7 . 10–3 Mean free path: ℓ = —————— cm air at room temperature P [mbar]
5 Temperature: °C = K – 273 = — (°F – 32) 9
Pressure: mbar Pa atm Torr Psi 1 mbar =1 100 9.87·10–4 0.75 1.45·10–2 1 Pa = 0.01 1 9.87·10–6 7.50·10–3 1.45·10–4 1 atm = 1013 1.01·105 1 760 14.696 1 Torr = 1.33 133 1.316·10–3 1 1.934·10–2 1 psi = 68.95 6895 6.804·10–2 51.71 1 122 back to Contents About us
Index
A M Airborne 76 Magnetron Sputtering 21, 26, 76 Aluminum coatings 31, 54 Metal coatings 54 Atomic layer deposition 22 MgF2 86, 91, 95, 105
B N Bandwidth 15 N-BK7 86, 89
C O CaF2 86, 91, 95, 105 OPO 56, 70 Cavity Ring Down 113 Chirped mirrors 66 P Cleaning substrates 110 Polarizer 46 Coating types 8 Contact Cover III R Crystals 72 Reflection filter 52 Refractive index 86, 95, 96 D DIN ISO 10110 82 S Sapphire 86, 90, 94, 105 E Silicium 86, 92, 95 Electron Beam Evaporation 21, 23 Silver coatings 54, 63 Etalons 104 Spaceborne 76 Excimer 30, 32 Sputtered coatings 20, 26, 27, 61, 73, 75 EXPRESS 4 Substrate materials 86
F T Fibers 73 Thermal evaporation 23 Focal length 100, 102, 112 Fused Silica 86, 88, 95 U UHV-window 73 G GD 113 V GDD 16, 61, 113 Variable coatings 11, 48 Germanium 86, 93 Gold coatings 45, 54 W Gradient coatings 50 Wafer 72 GTI 64 Wavelength shift 15 GVD 94 Wedges 98
H Y Harmonics 40 YAG 86, 90, 105
I Z Ion Assisted Deposition 21, 24 Zinc Selenide 86, 92, 95, 105 Ion Beam Sputtering 21, 27, 58, 61, 75 Ion Plating 21, 25
L Large optics 74 Lenses 100 LIDT 17, 114 LOOP 5 Low loss 75 123 Appendix
References
LASEROPTIK has many customers worldwide, small and large and in between.
The confidentiality of information about our customers, their products and technologies is very important to us.
Nevertheless we gratefully appreciate to be able to name the following, authorized references: 124 back to Contents About us
Final questions
1) How many frogs did you find in this catalog? 2) How much thicker is a human hair compared to a standard coating HR 1064 nm / 0°? 3) How many optics were needed to build the globe on the back cover? 4) Did you see the EXPRESS dog running through the pages?? 5) Which coating was first entered into our data system? 6) Do you have any questions? 7) What do we have to take into account for your quotation? Find the hidden words.
LIUZTRPEWQADANKESDFGHIF LOSSESACOHRADI FF ICULTYJ LMENBVLCXAYASDFRGHFRODL AWSXENAZGRUTEMPERATUREL CADFTGVGZDI ILOPDLKFBJBO HVQWEEARTNZFLUIOPIAESED EEGJENNYDEFFICIENCYTLRN NLUZYVHSJSKALMNDBVKT ITU OERDSI AGISYNXCTKELLYDVO KNSFGRHLJOKYSHERTAALTPF IGUEHOMOGENEI TYRTZRUIOG ETLWQNARDSFSZGHCLEANING HHAPDMSI YX I ZECVHBNMLKJ E ESFAGERATHLRZVUASIGOPSR KZQUANTITYAEVFENCMARIAE NWHLNTBDGTSFCDENAWBASLT AIDAUJNMKIELL IMATERIALS DLOFRI EDAPRELMJUTEI ZHYA QMWEFL EDCVOCFRTL ENEGBNE SAXUCABSORPT I ONBRCLNNMY GCOSTSHJKOT I YX I C IVLSARA IYOKOEQWESIOTWOFNGEHJNS
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quantity, reflection, scattering, size, temperature, wavelengths (see comparison on page 21). And even more is hidden... is more even And 21). page on comparison (see wavelengths temperature, size, scattering, reflection, quantity,
7) Absorption, cleaning, costs, difficulty, efficiency, environment, GDD, hardness, homogeneity, LIDT, losses, materials, losses, LIDT, homogeneity, hardness, GDD, environment, efficiency, difficulty, costs, cleaning, Absorption, 7)
6) Contact us, see cover III or next page. next or III cover see us, Contact 6)
18,000 different coating designs. coating different 18,000
5) HT 532 nm HR 1064 nm / 0° [B-00001] was the first coating we entered into our system, see page 41. Today the system shows more than more shows system the Today 41. page see system, our into entered we coating first the was [B-00001] 0° / nm 1064 HR nm 532 HT 5)
4) Use the lower right corner of this catalogue as flip-book. as catalogue this of corner right lower the Use 4)
3) The globe is built out of 1429 coated optics. Doesn`t it look pretty? look it Doesn`t optics. coated 1429 of out built is globe The 3)
2) A human hair is about 10-20 times thicker than a standard coating HR1064 nm / 0° (see information on page 13). page on information (see 0° / nm HR1064 coating standard a than thicker times 10-20 about is hair human A 2) 1) Two frogs can be seen, one placed into each coating machine on page 24 and 25. and 24 page on machine coating each into placed one seen, be can frogs Two 1) 100 90
[%] 80 70 Design 60 50 Text / 40 30 20 10 0 010 040302 50 60 70 80 90 100 page 124
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