1 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 1. Photo objective lens 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 -