Post on 13-Jun-2020
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