Design and Correction of optical Systems

1 Design and Correction of optical Systems Part 14: Optical system classification Summer term 2012 Herbert Gross Overview 1. Basics 2012-04-18 2...
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Design and Correction of optical Systems Part 14: Optical system classification Summer term 2012 Herbert Gross

Overview

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

2012-04-18

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 field and aperture size

photographic Biogon

40° lithography Braat 1987

Scheme is related to size, correction goals and etendue of the systems

36° 32° Triplet Distagon

28°

Aperture dominated: Disk lenses, microscopy, Collimator Field dominated: Projection lenses, camera lenses, Photographic lenses

24° Sonnar

20° projection

16° 12°

double Gauss

split triplet

projection

projection Gauss



lithography 2003

diode collimator

achromat



0

0.2

0.4

micro 100x0.9

micro 40x0.6

micro 10x0.4



Spectral widthz as a correction requirement is missed in this chart

constant etendue

Petzval

disc

0.6

0.8

microscopy collimator focussing

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

10. Lithography projection lens

M3

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

eye

14. Stereo microscope

eyepiece tube system

zoom system

common objective lens

object plane stereo angle

common axis

15. Zoom system f = 61

f = 113

f = 166

Achromate

Achromate: - Axial colour correction by cementing two different glasses - Bending: correction of spherical aberration at the full aperture - Aplanatic coma correction possible be clever choice of materials

Crown in front

Four possible solutions: - Crown in front, two different bendings - Flint in front, two different bendings Typical: - Correction for object in infinity - spherical correction at center wavelength with zone - diffraction limited for NA < 0.1 - only very small field corrected

Flint in front

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

3. Achromatic correction condition Individual power values

F1

ν1

+

F1 =

F2

ν2

=0

1

ν 1− 2 ν1

⋅F

F2 =

1

ν 1− 1 ν2

⋅F

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: 3 radii, 2 indices, ratio ν1/ν2 Correction of spherical aberration: diverging cemented surface with positive spherical contribution for nneg > npos ∆ s' rim

Choice of glass: possible goals 1. aplanatic coma correction 2. minimization of spherochromatism 3. minimization of secondary spectrum

case with 2 solutions

R

Bending has no impact on chromatical correction: is used to correct spherical aberration at the edge Three solution regions for bending 1. no spherical correction 2. two equivalent solutions 3. one aplanatic solution, very stable

case without solution, only sperical minimum

1

case with one solution and coma correction

Achomatic solutions in the Glass Diagram

flint negative lens

crown positive lens Achromat

Achromate

Achromate

Longitudinal aberration Transverse aberration Spot diagram

486 nm ∆y' λ = 486 nm

axis

rp 1 λ = 656 nm sinu' λ = 587 nm

1.4°

486 nm 587 nm 656 nm

2° 0

0.1

0.2

∆s' [mm]

587 nm

656 nm

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 :

D θG = f

Diffraction part:

θD =

λ D

Defocussing contribution to divergence

∆θ = −

2∆ z ⋅ sin u f divergence θG/2

source

u

D

f

Collimator Optics

0.1

Monochromatic doublet Correction only spherical and coma: Seidel surface contributions Limiting : astigmatism and curvature

spherical

0 -0.1 5

coma

0 -5 2

astigmatism

0 -2

2

curvature

0 -2

Enlarged aperture : meniscus added

4

distortion

2 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

b) NA = 0.187

Wrms 0.2

NA = 0.124 NA = 0.187 NA = 0.277

0.15

c) NA = 0.277 0.1 diffraction limit 0.05

0

0

0.1

0.2

0.3

0.4

0.5

w [°]

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 1.2 tube with tube lens and

eyepiece

binocular beam splitter 1.3 eyepieces 1.4 optional equipment for photo-detection

intermediate image binocular beamsplitter

tube lens

collector

2. Illumination 2.1 lamps with collector and filters

lamp

objective lens

object

2.2 field aperture 2.3 condenser with aperture stop

condensor

collector

lamp

Microscope Objective Lens 0.5

Seidel surface contributions

spherical

-0.5

for 100x/0.90 No field flattening group

0

0.02

coma

0 -0.02

Lateral color in tube lens corrected astigmatism

4 2 0 -2 -4 5

curvature

0 -5 2

distortion

0 -2 0.02

axial chromatic

0 -0.02 1

lateral chromatic

0 -1

1

sum

10

5

13 11 1

5

8

Microscope Objective Lens: Flattening

Three different classes: 1. No effort 2. Semi-flat

DS

3. Completely flat 1

not plane

0.8

plane diffraction limit

0.6

0.4 semi plane

0.2

0 0

0.5

0.707

1

rel. field

Microscope Objective Lens

Possible setups for flattening the field

a) single meniscus lense

Goal: - reduction of Petzval sum - keeping astigmatism corrected

b) two meniscus 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

Quasi-Symmetrical Angle

Extrem Wide Angle

Topogon

Fish Eye

Telecentric I

Metrogon

Telecentric II

Families of photographic lenses Long history Not unique

Compact

Pleon Super-Angulon

Hypergon Telephoto

Panoramic Lens

Wide Angle Retrofocus Retrofocus

Pleogon

Hologon

SLR

Flektogon Distagon

Catadioptric

Plastic Aspheric I

Plastic Aspheric II

IR Camera Lens

UV Lens

Biogon

Triplets Vivitar

Retrofocus II

Singlets Less Symmetrical Landscape

Ernostar II

Ernostar

Triplet

Pentac

Heliar

Hektor

Achromatic Landscape

Inverse Triplet

Sonnar

Petzval

Symmetrical Doublets Petzval Projection

Petzval, Portrait

Dagor

Rapid Rectilinear Aplanat

Quadruplets Double Gauss Biotar / Planar

Petzval,Portrait flat

Ultran

Double Gauss II

Noctilux

Kino-Plasmat

Celor

Dagor reversed

Periskop

Quasi-Symmetrical Doublets Orthostigmatic Tessar

Plasmat

R-Biotar

Unar

Protar

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

Distance t increased First lens fixed

changed distance t

moved lens

changed focal length f

Change of Focal Length

Distance t increased Image plane fixed

two lenses moved t

f

image plane

Performance Variation over z

System layout

f1

f2

f = 50 mm t2

f = 67 mm

f = 100 mm

f = 133 mm

f = 200 mm

f3

f4

Performance Variation over z

Seidel spherical aberration

surface contrib.

coma

0.1

5

0.1

0.5

0

0

0

-0.1

-0.1

-0.5

lens 1

1

2

3

4

5

-0.2 1 0.2

2

3

4

0

0

-0.1

-0.1

-0.5

2

3

4

5 -0.2 1 0.2

2

3

4

0

0

-0.1

-0.1

-0.5

2

3

4

5 -0.2 1 0.2

2

3

4

0

0

0

-0.1

-0.1

0.5

3

4

5 -0.2 1

3

4

5

1

2

3

4

5

1

2

3

4

5

1

2

3

4

5

1

2

3

4

5

0 -5

2

3

4

1

5

2

3

4

5 5 0

0

-5

2

3

4

5

2

3

4

1

5

2

3

4

5

5 0.5

2

2

0

1

5

0.1

1

1

5

-5

0.1

sum

4

5

0

1

3

5

1

5 0.5

lens 3

2

-5

0.1

0.1

-5

5

0

1

0

0

1

5 0.5

lens 2

5

-5

0.1

0.1

lateral chromatical

axial chromatical

distortion

0.2

5 0

0

-5 -5 1

2

3

4

5

1

2

3

4

5

Zoom Lens

group 1

Zoom lens Three moving groups

group 2

group 3 e) f' = 203 mm w = 5.64° 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 focus

-Γ>0

Eyepiece

Eye pupil telescope focal length f T

Galilei typ: - no internal focus

Telescope pupil

eyepiece focal length f E

b) Galilei

- shorter total track -Γ