www.iap.uni-jena.de

Optical Design with Zemax

for PhD - Basics

Lecture 2: Basic Zemax handling

2014-04-24

Herbert Gross

Summer term 2014

2

Preliminary Schedule

No Date Subject Detailed content

1 16.04. Introduction

Zemax interface, menus, file handling, system description, editors, preferences,

updates, system reports, coordinate systems, aperture, field, wavelength, layouts,

raytrace, diameters, stop and pupil, solves, ray fans, paraxial optics

2 23.04. Basic Zemax handling surface types, quick focus, catalogs, vignetting, footprints, system insertion, scaling,

component reversal

3 30.04. Properties of optical systems aspheres, gradient media, gratings and diffractive surfaces, special types of

surfaces, telecentricity, ray aiming, afocal systems

4 07.05. Aberrations I representations, spot, Seidel, transverse aberration curves, Zernike wave

aberrations

5 14.05. Aberrations II PSF, MTF, ESF

6 21.05. Optimization I algorithms, merit function, variables, pick up’s

7 28.05. Optimization II methodology, correction process, special requirements, examples

8 04.06. Advanced handling slider, universal plot, I/O of data, material index fit, multi configuration, macro

language

9 11.06. Imaging Fourier imaging, geometrical images

10 18.06. Correction I simple and medium examples

11 25.06. Correction II advanced examples

12 02.07. Illumination simple illumination calculations, non-sequential option

13 09.07. Physical optical modelling I Gaussian beams, POP propagation

14 16.07. Physical optical modelling II polarization raytrace, polarization transmission, polarization aberrations, coatings,

representations, transmission and phase effects

15 23.07. Tolerancing Sensitivities, Tolerancing, Adjustment

1. Surface types

2. Glass catalogs

3. Lens Catalogs

4. Quick focus and adjustment

5. Vignetting

6. Foorprints

7. System changes

8. Delano diagram

3

Content

Setting of surface properties

local tilt

and

decenterdiameter

surface type

additional drawing

switches

coatingoperator and

sampling for POP

scattering

options

Surface properties and settings

Special surface types

Data in Lens Data Editor or in Extra Data Editor

Gradient media are descriped as 'special surfaces'

Diffractive / micro structured surfaces described by simple ray tracing model in one order

5

Important Surface Types

Standard spherical and conic sections

Even asphere classical asphere

Paraxial ideal lens

Paraxial XY ideal toric lens

Coordinate break change of coordinate system

Diffraction grating line grating

Gradient 1 gradient medium

Toroidal cylindrical lens

Zernike Fringe sag surface as superposition of Zernike functions

Extended polynomial generalized asphere

Black Box Lens hidden system, from vendors

ABCD paraxial segment

6

Important Surface Types

Diffraction grating

Classical grating with straight lines

Parameters: LP/mm, diffraction order

Substrate can be curved, lines are straight in the local coordinate system on the surface

Elliptical grating 1:

Similar, but grooves can be curved for projection onto x-y-plane,

Substrate can be aspheric

Elliptical grating 2:

Similar to 1, but curved lines defined by intersection of planes with asphere

Binary1

Substrate rotational symmetric asphere

Phase of binary element: extended polynomial, scaled on normalization radius in radiant

7

Diffractive Surfaces in Zemax

Binary2

Similare to 1, but phase only circular symmetric

Binary3

Substrate and phase circular symmetric

Two different data sets on two ring zones

Binary4

Similar to 3, but several zones possible

8

Diffractive Surfaces in Zemax

Radial grating

Grating with circular symmetry and a line spacing, which changes

over the radius

Variable line space grating

Straight lines but unevenly separated

Hologram 1

Hologram 2

Toroidal hologram

Optically fabricated hologram

Defined by corresponding lens systems to generate the interference with residual

aberrations

Toroidal grating

Cylindrical surface with usual line grating structure

Extended toroidal grating

9

Diffractive Surfaces in Zemax

Dispersion

n()

ni()

o

normal normalanomal

n

Dispersion:

Refractive index changes with wavelength

Normale dispersion: larger index n for shorter wavelengths,

Ray bending of blue rays stonger than red

Notice:

Diffraction dispersion is anomalous

with dn/d > 0

The different sign allows for chromatic

correction in diffractive elements.

21 nnn

d n

d 0

refractive

index n

1.65

1.6

1.5

1.8

1.55

1.75

1.7

BK7

SF1

0.5 0.75 1.0 1.25 1.751.5 2.0

1.45

flint

crown

Description of dispersion:

Abbe number

Visual range of wavelengths:

typically d,F,C or e,F’,C’ used

Typical range of glasses

ne = 20 ...100

Two fundamental types of glass:

Crown glasses:

n small, n large, dispersion low

Flint glasses:

n large, n small, dispersion high

n

n

n nF C

1

' '

ne

e

F C

n

n n

1

' '

Dispersion and Abbe number

11

Usual representation of

glasses:

diagram of refractive index

vs dispersion n(n)

Left to right:

Increasing dispersion

decreasing Abbe number

Glass Diagram

12

Schott formula

empirical

Sellmeier

Based on oscillator model

Bausch-Lomb

empirical

Herzberger

Based on oscillator model

Hartmann

Based on oscillator model

n a a a a a ao

1

2

2

2

3

4

4

6

5

8

n A B C( )

2

212

2

222

n A B CD E

Fo

o

( )

( )

2 4

2

2

2 22

2 2

mmit

aaaan

o

oo

o

168.0

)(222

3

22

22

1

5

4

3

1)(a

a

a

aan o

Dispersion formulas

13

Relative partial dispersion :

Change of dispersion slope with

Different curvature of dispersion curve

Definition of local slope for selected

wavelengths relative to secondary

colors

Special -selections for characteristic

ranges of the visible spectrum

= 656 / 1014 nm far IR

= 656 / 852 nm near IR

= 486 / 546 nm blue edge of VIS

= 435 / 486 nm near UV

= 365 / 435 nm far UV

P

n n

n nF C

1 2

1 2

' '

n

400 600 800 1000700500 900 1100

e : 546 nm

main color

F' : 480 nm

1. secondary

color

g : 435 nmUV edge

C' : 644 nm

s : 852 nm

IR edge

t : 1014 nm

IR edge

C : 656 nmF : 486 nm

d : 588 nm

i : 365 nm

UV edge

i - g

F - C

C - s

C - t

F - e

g - F

2. secondary

color

1.48

1.49

1.5

1.51

1.52

1.53

1.54

n()

Relative Partial Dispersion

14

Anormal partial dispersion and normal line

Partial Dispersion

15

Pg,F

0.5000

0.5375

0.5750

0.6125

0.6500

90 80 70 60 50 40 30 20

F2

F5

K7

K10

LAFN7

LAKN13

LAKL12

LASFN9

SF1

SF10

SF11

SF14

SF15

SF2

SF4

SF5

SF56A

SF57

SF66

SF6

SFL57

SK51

BASF51

KZFSN5

KZFSN4

LF5

LLF1

N-BAF3

N-BAF4

N-BAF10

N-BAF51N-BAF52

N-BAK1

N-BAK2

N-BAK4

N-BALF4

N-BALF5

N-BK10

N-F2

N-KF9

N-BASF2

N-BASF64

N-BK7

N-FK5

N-FK51N-PK52

N-PSK57

N-PSK58

N-K5

N-KZFS2

N-KZFS4

N-KZFS11

N-KZFS12

N-LAF28

N-LAF2

N-LAF21N-LAF32

N-LAF34

N-LAF35

N-LAF36

N-LAF7

N-LAF3

N-LAF33

N-LAK10

N-LAK22

N-LAK7

N-LAK8

N-LAK9

N-LAK12

N-LAK14

N-LAK21

N-LAK33

N-LAK34

N-LASF30

N-LASF31

N-LASF35

N-LASF36

N-LASF40

N-LASF41

N-LASF43

N-LASF44

N-LASF45

N-LASF46

N-PK51

N-PSK3

N-SF1

N-SF4

N-SF5

N-SF6

N-SF8

N-SF10

N-SF15

N-SF19

N-SF56

N-SF57

N-SF64

N-SK10

N-SK11

N-SK14

N-SK15

N-SK16

N-SK18N-SK2

N-SK4

N-SK5

N-SSK2

N-SSK5

N-SSK8

N-ZK7

N-PSK53

N-PSK3

N-LF5

N-LLF1

N-LLF6

BK7G18

BK7G25

K5G20

BAK1G12

SK4G13

SK5G06

SK10G10

SSK5G06

LAK9G15

LF5G15

F2G12

SF5G10

SF6G05

SF8G07

KZFS4G20

GG375G34

n

normal

line

Selection of glass catalogs in

GENERAL / GLASS CATALOGS

Viewing of dispersion curves

ANALYSIS / GLASS AND GRADIENT

Viewing of glass map

16

Glasses in Zemax

Selection of glass catalogs in

GENERAL / GLASS CATALOGS

use your own catalog

Viewing of glass properties in

ANALYSIS / GLASS AND GRADIENT

glass map (zoom in)

Glasses in Zemax

Ref.: B. Böhme 17

Viewing of transmission curves

also for several glasses in comparison

ANALYSIS / GLASS AND GRADIENT

Definition of a glass as a variable point in the

map (model glass)

18

Glasses in Zemax

Viewing of glass properties in

ANALYSIS / GLASS AND GRADIENT

transmisson

dispersion

dispersion vs wavelength

comparison of max 4 glasses

Glasses in Zemax

19 Ref.: B. Böhme

For optimization

Definition of a glass as a variable

point in the glass map

model glass

Establish own glass catalogs with

additional glasses

preferred choices

as an individual library

Glasses in Zemax

20 Ref.: B. Böhme

choice of 4 dispersion formula

after fit:

- pv and rms of approximation visible

- no individual errors seen

check results for suitable accuracy,

especially at wavelengths and

temperatures with sparse input data

and at intervall edges

add to catalog

enter additional data

Save catalog

Material Index Fit

21 Ref.: B. Böhme

Establishing a special own

material

Select menue:

Tools / Catalogs / Glass catalogs

Options:

1. Fit index data

2. Fit melt data

Input of data for wavelengths

and indices

It is possible to establish own

material catalogs with additional

glasses as an individual library

22

Material Index Fit

Melt data:

- for small differences of real materials

- no advantage for new materials

Menue option:

‚Glass Fitting Tool‘

don‘t works (data input?)

23

Material Index Fit

Menue: Fit Index Data

Input of data: 2 options:

1. explicite entering wavelengths and indices

2. load file xxx.dat with two columns:

wavelength in m and index

Choice of 4 different dispersion formulas

After fit:

- pv and rms of approximation visible

- no individual errors seen

- new material can be added to catalog

- data input can be saved to file

24

Material Index Fit

Lens catalogs:

Data of commercial lens vendors

Searching machine for one vendor

Componenets can be loaded or inserted

Preview and data prescription possible

Special code of components in brackets

according to search criteria

25

Lens Catalogs

Some system with more than one lens available

Sometimes:

- aspherical constants wrong

- hidden data with diameters, wavelengths,...

- problems with old glasses

Data stored in binary .ZMF format

Search over all catalogs not possible

Catalogs changes dynamically with every release

Private catalog can be generated

26

Lens Catalogs

Stock Lens Matching

This tool swaps out lenses in a design to the nearest equivalent candidate out of a

vendor catalogue

It works together with the merit function requirements (with constraints)

Aspheric, GRIN and toroidal surfaces not supported; only spherical

Works for single lenses and achromates

Compensation due to thickness adjustments is optional

Reverting a lens to optimize (?)

Top results are listed

Combination of best single lens substitutions is possible.

Overall optimization with nonlinear interaction ?

Ref.: D. Lokanathan

Stock Lens Matching

Selectioin of some vendors by

CNTR SHIFT marking

Ref.: D. Lokanathan

Stock Lens Matching

Output

Ref.: D. Lokanathan

In the menue TOOLS – DESIGN – QUICK FOCUS we have the opportunity to adjust

the image location according to the criteria

1. Spot diameter

2. Wavefront rms

3. Angle radius

IN principle, this option is a simplified optimization

Example: find the best image

plane of a single lens

Spot before and after performing the

optimal focussing

30

Quick Focus Option

In the menue TOOLS – DESIGN – QUICK ADJUST we have the opportunity to adjust

1. one thickness

2. one radius

similar to the quick focus function some where in the system.

But: the effect is iterative, in case of nonlinearities, some calls are necessary

Special application: adjust the air distance before a collimation lens to get the best collimation

As criteria, wavefroint, spot diameter of angular radius ar possible

Example: Move a lens in between a

system to focus the image

Spots before and after thew adjustment

31

Quick Adjust Option

Cardinal elements of a selected index range

(lens or group)

32

Cardinal Elements in Zemax

Artificial vignetting:

Truncation of the free area

of the aperture light cone

Natural Vignetting:

Decrease of brightness

according to cos w 4 due

to oblique projection of areas

and changed photometric

distances

Vignetting

w

AExp

imaging without vignetting

complete field of view

imaging with

vignetting

imaging with

vignetting

field

angle

D

0.8 Daxis

field

truncation

truncation

stop

33

3D-effects due to vignetting

Truncation of the at different surfaces for the upper and the lower part

of the cone

Vignetting

object lens 1 lens 2 imageaperture

stop

lower

truncation

upper

truncation

sagittal

trauncation

chief

ray

coma

rays

34

Truncation of the light cone

with asymmetric ray path

for off-axis field points

Intensity decrease towards

the edge of the image

Definition of the chief ray:

ray through energetic centroid

Vignetting can be used to avoid

uncorrectable coma aberrations

in the outer field

Effective free area with extrem

aspect ratio:

anamorphic resolution

Vignetting

projection of the

rim of the 2nd lens

projection of the

rim of the 1st lens

projection of

aperture stop

free area of the

aperture

sagittal

coma rays

meridional

coma rayschief

ray

35

Vignetting

Illumination fall off in the image due to vignetting at the field boundary

36

Looking for the

ray bundle cross

ections

37

Footprints

Useful commands for system changes:

1. Scaling (e.g. patents)

2. Insert system

with other system file

File - Insert Lens

2. Reverse system

38

System changes

Delano Diagram

Special representation of ray bundles in

optical systems:

marginal ray height

vs.

chief ray height

Delano digram gives useful insight into

system layout

Every z-position in the system corresponds

to a point on the line of the diagram

Interpretation needs experience

CRyy

lens

y

field lens collimatormarginal ray

chief ray

y

y

y

lens at

pupil

position

field lens

in the focal

plane

collimator

lens

MRyy

40

Delano Diagram

Delano’s

skew ray

Image

d2 d1

yC yM

(yC,yM) yM

a a

b

c c

d d

yC Delano ray (blue)=

Chief ray (red) in x +

Marginal ray (green) in y

Delano Diagram =

Delano ray projected

into the xy-Plane

Substitution

x -->

y = Pupil coordinate

= yc Field coordinate

Stop

Lens

a b

c

d

y (or yM)

y

y

y

Ref.: M. Schwab / M. Geiser

chief ray

marginal ray

Delano diagram:

projection

along z

b

x

y

marginal

ray

chief

ray

skew ray

y

y

y

y

diagram

image

object

Pupil locations:

intersection points with y-axis

Field planes/object/image:

intersectioin points with y-bar axis

Construction of focal points by

parallel lines to initial and final line

through origin

y

y

object

plane

lens

image

plane

stop and

entrance pupil

exit pupil

y

y

object

space

image

space

front focal

point Frear focal

point F'

Delano Diagram

Delano Diagram

Influence of lenses:

diagram line bended

Location of principal planes

y

y

strong positive

refractive power

weak positive

refractive power

weak negative

refractive power

y

y

object space image space

principal

plane

yP

yP

Delano Diagram

Microscopic system

y

y

eyepiece

microscope

objective tube lens

object

image at infinity

aperture

stop

intermediate

image

exit pupil

telecentric

Kepler telescope with field lens

Microscopic illumination

Delano Diagram

y

y

lens 1

objective

lens 2

eyepiece

field lens

intermediate

image

y

source

field

stop

aperture

stopcondenser

collector

Delanos y-ybar diagram

Simple implementation in Zemax

45

Delano Diagram in Zemax

Example:

- Lithographic projection lens

- the bulges can be seen by characteristic arcs

- telecentricity: vertical lines

- diameter variation

- pupil location

46

Delano Diagram in Zemax

telecentric

image

telecentric

object

pupil

largest beam

diameter: surface 19

Dmax/2

1

23456

78

910

11

12

13

1415

16171819

2021

22

2324

2526

27

28

29

3031

32333435

3637

3839

40

41

42

430

smallest

beam

diameter:

surface 25

yMR

yCR

negative

lenses

positive

lenses