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Design and Correction of optical Systems
Part 14: Optical system classification
Summer term 2012 Herbert Gross Overview
2012-04-18 1. Basics 2012-04-18 2. Materials 2012-04-25 3.Components 2012-05-02 4. Paraxial optics 2012-05-09 5. Properties of optical systems 2012-05-16 6.Photometry 2012-05-23 7. Geometrical aberrations 2012-05-30 8. Wave optical aberrations 2012-06-06 9. Fourier optical image formation 2012-06-13 10.Performance criteria 1 2012-06-20 11.Performance criteria 2 2012-06-27 12.Measurement of system quality 2012-07-04 13.Correction of aberrations 1 2012-07-11 14.Optical system classification 2012-07-18 Content
14.1 Overview and classification 14.2 Achromate 14.3 Collimator 14.4 Microscope optics 14.5 Photographic optics 14.6 Zoom lenses 14.7 Telescopes 14.8 Miscellaneous 14.9 Lithographic projection systems Field-Aperture-Diagram
w ° Classification of systems with photographic Biogon field and aperture size 40° lithography Braat 1987 ° Scheme is related to size, 36° correction goals and etendue 32° of the systems Triplet 28° Distagon ° Aperture dominated: 24° Disk lenses, microscopy, Sonnar Collimator 20°
projection 16° ° Field dominated: split double triplet Gauss lithography Projection lenses, 12° 2003 camera lenses, projection projection constant Gauss Petzval etendue 8° Photographic lenses micro micro micro micros- 100x0.9 10x0.4 40x0.6 copy 4° achromat diode collimator ° Spectral widthz as a correction disc collimator focussing 0° requirement is missed in this chart 00.2 0.4 0.6 0.8 NA Typical Example Systems 1
2. Microscope objective lens
3. Binocular
4. Infrared afocal system Typical Example Systems 2
5. Relay optics
6. Scan-objective lens
7. Collimator objective lens
possible surfaces under test Typical Example Systems 3
8. Projector lens
9. Telescope M1
M2
M3 10. Lithography projection lens Typical Example Systems 4
11. Illumination collector system
12. Illumination condenser system
image
free formed surface 13. Head mounted display total internal reflection
eye pupil
free formed surface
field angle 14° Typical Example Systems 5
eyepiece eye 14. Stereo microscope tube system zoom common system objective object lens plane stereo angle common axis
15. Zoom system
f = 61
f = 113
f = 166 Achromate
° Achromate: - Axial colour correction by cementing two Crown in different glasses front - Bending: correction of spherical aberration at the full aperture - Aplanatic coma correction possible be clever choice of materials
° Four possible solutions: - Crown in front, two different bendings - Flint in front, two different bendings Flint in front ° Typical: - Correction for object in infinity - spherical correction at center wavelength with zone - diffraction limited for NA < 0.1 - only very small field corrected
solution 1 solution 2 Achromate: Realization Versions
° Advantage of cementing: solid state setup is stable at sensitive middle surface with large curvature
° Disadvantage: loss of one degree of freedom
° Different possible realization forms in practice Achromate : Basic Formulas
° Idea: 1. Two thin lenses close together with different materials 2. Total power F = F1 + F2
F F 3. Achromatic correction condition 1 + 2 = 0 ν1 ν 2 1 1 ° Individual power values F = ⋅ F = ⋅ 1 ν F2 ν F 1− 2 1− 1 ν 1 ν 2 ° Properties: 1. One positive and one negative lens necessary 2. Two different sequences of plus (crown) / minus (flint) 3. Large ν-difference relaxes the bendings 4. Achromatic correction indipendent from bending 5. Bending corrects spherical aberration at the margin 6. Aplanatic coma correction for special glass choices 7. Further optimization of materials reduces the spherical zonal aberration Achromate: Correction
° Cemented achromate: 6 degrees of freedom: ν ν 3 radii, 2 indices, ratio 1/ 2
° Correction of spherical aberration: diverging cemented surface with positive spherical contribution for n neg > n pos ∆∆∆ s'rim ° Choice of glass: possible goals 1. aplanatic coma correction 2. minimization of spherochromatism case with 2 solutions 3. minimization of secondary spectrum
R ° Bending has no impact on chromatical 1 correction: is used to correct spherical aberration case with one solution at the edge and coma case without solution, correction only sperical minimum ° Three solution regions for bending 1. no spherical correction 2. two equivalent solutions 3. one aplanatic solution, very stable Achomatic solutions in the Glass Diagram
flint crown negative lens positive lens
Achromat Achromate
° Achromate
° Longitudinal aberration ° Transverse aberration ° Spot diagram 486 nm 587 nm 656 nm ∆∆∆y'
λλλ = 486 nm axis
rp 1
λλλ = 656 nm sinu' λλλ = 587 nm 1.4° 486 nm 587 nm 656 nm
2° ∆∆∆s' [mm] 0 0.1 0.2 Achromate
° Residual aberrations of an achromate ° Clearly seen: 1. Distortion 2. Chromatical magnification 3. Astigmatism Collimation
° Collimating source radiation: Finite divergence angle is reality ° Geometrical part due to finite size : θ === D G f ° Diffraction part: λ θ === D D ° Defocussing contribution to divergence 2∆z ∆θ=== −−− ⋅⋅⋅sin u f
θθθ divergence G/2
source u D
f Collimator Optics
0.1 spherical ° Monochromatic doublet 0
° Correction only spherical and coma: -0.1
Seidel surface contributions 5 coma Limiting : astigmatism and curvature 0 -5
2 astigmatism 0 -2
2
curvature 0
-2 ° Enlarged aperture : meniscus added 4 2 distortion 0 -2 -4 1 2 3 4 sum Collimator Optics
° Enlarging numerical aperture by aplanatic-concentric meniscus lenses ° Extreme good correction of spherical aberration
a) NA = 0.124
W b) NA = 0.187 rms 0.2 NA = 0.124 NA = 0.187 NA = 0.277 0.15 c) NA = 0.277
0.1 diffraction limit
0.05
0 w [°] 0 0.1 0.2 0.3 0.4 0.5 Microscopy - Image Planes and Pupils
° Upper row : image planes ° Lower row : pupil planes ° Köhler setup Upright-Microscope
film plane ° Sub-systems:
1. Detection / Imaging path photo camera 1.1 objective lens eyepiece 1.2 tube with tube lens and binocular beam splitter 1.3 eyepieces 1.4 optional equipment intermediate image tube lens lamp for photo-detection binocular beamsplitter
collector 2. Illumination objective 2.1 lamps with collector and filters lens object 2.2 field aperture condensor 2.3 condenser with aperture stop
collector
lamp Microscope Objective Lens
0.5 ° Seidel surface contributions spherical 0 -0.5
for 100x/0.90 0.02
coma 0
° No field flattening group -0.02
4 ° Lateral color in tube lens corrected 2 astigmatism 0 -2 -4
5 curvature 0 -5
2 distortion 0 -2
0.02
axial 0 chromatic -0.02
1 lateral 0 chromatic -1
1 5 10 sum
13 11
8 1 5 Microscope Objective Lens: Flattening
° Three different classes: 1. No effort 2. Semi-flat D 3. Completely flat S 1
not plane plane 0.8 diffraction limit 0.6
0.4 semi plane 0.2
rel. 0 field 0 0.5 0.707 1 Microscope Objective Lens
a) ° Possible setups for flattening single meniscus the field lense ° Goal: b) - reduction of Petzval sum two meniscus - keeping astigmatism corrected lenses
c) symmetrical triplet
d) achromatized meniscus lens
e) two meniscus lenses achromatized
f) modIfied achromatized triplet solution Microscopic Objective Lens
mechanical setup Classification
Special Extrem Wide Angle Quasi-Symmetrical Angle Topogon Telecentric I Fish Eye Metrogon
Telecentric II Compact ° Families of photographic lenses Pleon Super-Angulon Hypergon Telephoto Catadioptric ° Long history Panoramic Lens
° Not unique Wide Angle Retrofocus Pleogon Hologon Plastic Plastic Aspheric Retrofocus SLR Aspheric I II
IR Camera Lens UV Lens
Flektogon Biogon Distagon
Triplets
Retrofocus II Vivitar Triplet Pentac
Singlets Heliar Hektor Less Symmetrical Achromatic Landscape Landscape Ernostar Ernostar II
Inverse Triplet
Sonnar
Petzval Symmetrical Doublets
Petzval, Portrait Petzval Dagor Rapid Projection Rectilinear Aplanat Quadruplets Petzval,Portrait flat R-Biotar Double Gauss Ultran Dagor Biotar / Planar reversed Periskop
Double Gauss II Quasi-Symmetrical Doublets Noctilux Orthostigmatic Tessar Protar
Plasmat Celor Kino-Plasmat Unar Antiplanet Angulon Photographic Lenses
° Tessar ° Distagon
° Double Gauss
° Tele system
° Super Angulon
° Wide angle Fish-eye Retrofocus Lenses
° Example lens 2
° Distagon Fish-Eye-Lens
° Nikon 210°
° Pleon (air reconnaissance) Change of Focal Length
changed moved ° Distance t increased distance lens t changed focal ° First lens fixed length f Change of Focal Length
° Distance t increased two lenses moved image t f plane ° Image plane fixed Performance Variation over z
° System layout f1 f2 f3 f4
f = 50 mm
t2
f = 67 mm
f = 100 mm
f = 133 mm
f = 200 mm Performance Variation over z
Seidel spherical aberration coma distortion axial chromatical lateral chromatical 0.2 surface 5 5 0.1 0.1 0.5 contrib. lens 1 0 0 0 0 0
-0.1 -0.1 -0.5 -5 -5 -0.2 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 0.2 5 5 0.1 0.1 0.5 lens 2 0 0 0 0 0
-0.1 -0.1 -0.5 -5 -5 -0.2 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 0.2 5 5 0.1 0.1 0.5 lens 3 0 0 0 0 0
-0.1 -0.1 -0.5 -5 -5 -0.2 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 0.2 5 5 0.1 0.1 0.5 sum 0 0 0 0 0 - -0.1 -5 -0.1 0.5 -5 1 2 3 4 5 -0.2 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5 Zoom Lens
group 1 group 2 group 3
° Zoom lens e) f' = 203 mm w = 5.64° ° Three moving groups F# = 16.6
d) f' = 160 mm w = 7.13° F# = 13.7
c) f' = 120 mm w = 9.46° F# = 10.9
b) f' = 85 mm w = 13.24° F# = 8.5
a) f' = 72 mm w = 15.52° F# = 7.7 Basic Refractive Telescopes
° Kepler typ: - internal focus Telescope pupil a) Kepler/Fraunhofer - longer total track intermediate Eyepiece - Γ > 0 focus
Eye pupil
telescope focal length f T ° Galilei typ: eyepiece focal length f Telescope E - no internal focus pupil - shorter total track b) Galilei - Γ < 0
Eye pupil
telescope focal length f T
eyepiece focal
length f E Catadioptric Telescopes
L1 M1 ° Maksutov compact
L2 L3 L4, L5 M2
° Klevtsov M1
M2
L1, L2 Astronomical Telescope
Primary and secondary mirror Telecentric Systems
° Typical : system layout with two groups ° Telecentricity error due to vignetting ° Telecentricity forces large diameters
∆∆∆ 486 nm 587 nm 656 nm wtele [°] 0.9
0.8 axis 0.7 chief ray 0.6
0.5 centre ray 3° 0.4
0.3
0.2
0.1 5° 0
-0.1 y'/y' max 0 0.2 0.4 0.6 0.8 1 Relay Systems: Endoscopes
° Transport over large distances ° Combination of several relay subsystems ° Large field-angle objective lens ° Applications: Technical or medical
objective 1. relay 2. relay 3. relay
λλλ ° Different subsystems: Wrms [ ]
0.5
0.4 486 nm 587 nm 0.3 656 nm
0.2
0.1 diffraction limit y' 0 [mm] 0 0.4 0.8 1.2 1.6 2 Handy Phone Objective lenses
° Examples
Ref: T. Steinich Beam Guiding Systems
° Transport of laser light over large a) distances ΓΓΓ = 5 ° Adaptation of beam diameter ° Solutions : b) Telescopes of Kepler or Galilei type ΓΓΓ = 5
c) ΓΓΓ = 4
d) ΓΓΓ = 50
adjustment e) ΓΓΓ = 4 Beam Guiding Systems
dark colours : Kepler / bright colours : Galilei ° Comparison: 0.02 Kepler: spherical 0 - internal focus -0.02 0.01 - large overall length coma 0 Galilei: -0.01 2 - shorter length astigmatism 0 - better correction -2 2
curvature 0
-2 1
distortion 0
-1 1 2 3 4 sum Navarro Eye Model
° Wide angle model for larger fields 459 nm 550 nm 632 nm ° Parameters for all accomodations
° Description of chromatical aberrations 0°
15°
30° 20° 15° 20°
0°
30° Optical Illusion
The rings seems to move Abbe Orthoscopic Eyepiece
° Distortion corrected ° General problems with eyepieces: - remote eye pupil - typical eye relief 22 mm
LONGITUDINAL ASTIGMATIC SPHERICAl ABER. FIELD CURVES DISTORTION
1.000 8.000 8.000 18°
0.750 6.000 6.000
0.500 4.000 4.000 10°
0.250 2.000 2.000 n
0° i m c
-1.000 0.000 1.000 -3.000 0.000 3.000 -20.00 0.00 20.00 r
a
DIOPTER DIOPTER Distortion (%) 0 2 tan sag Scan System
a) standard distortion b) f- θθθ-distortion c) wave aberration ° Non-telecentric y/y y/y λλλ max max Wrms [ ] 1 1 ° Scan angle 2x30° 0.1 ° Monochromatic 0.08 0.06 ° F-θ-corrected 0.5 0.5 0.04
0.02
0 θθθ -10% 0 10% -0.2% 0 0.2% 0 15° 30°
0° 5° 10° 15°
20° 24° 28° 30.4° Lithographic Lenses
System with 1. Illumination (horizonthal) 2. Mask projection (vertical) Lithographic Lens Example Layouts
stop
reticle
mask
reticle
1. relay group
stop intermediate image reticle
mask
mirror with relay group
wafer 2. relay group Lithographic Optics
° EUV α-Tool 2008 50 Summary of Important Topics
° A possible classification of optical systems is a sorting into field size and aperture size ° Aperture, field size and width of wavelength range are responsable for complexity ° Achromate: chromatical and spherical correction ° Achromate: additional degree of freedom allows for coma correction or reduction of spherochromatism ° Achromate: different realization options possible ° There exist quite different types of optical systems with individual specific problems Outlook
Next lecture: Special lectures and applications in the context of optical design Date: Winter term / October 2012