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OPAC 202

Optical Design and Inst.

Chapter 10

Lens Catalog &

Test Plate Fitting

Department of

Optical & Acustical Engineering

Gaziantep University

http://www.gantep.edu.tr/~bingul/opac202

Apr 2020

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In this section, you will see three applications in Zemax:

1. How to see dispersion curve of an optical material

2. How to enter glass data at specific wavelengths

3. How to add a lens from the Lens Catalog

4. How to perform Test Plate Fitting

Introduction

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The index of refraction of an optical material varies with

wavelength. In Zemax, dispersion curve for a glass can be

obtained in Libraries Tab. Click on Material Analysis then

invoke Dispersion Diagram.

Example1: Dispersion Curve in Zemax

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Glass Companies

SCHOTT www.schott.com

OHARA CORP. www.oharacorp.com

HOYA GROUP www.hoya-opticalworld.com/english

ETC.

In Zemax go to:

General -> Glass Catalog

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SCHOTT N-BK7 (or BK7)

SCHOTT N-BK 7 (517642.251)

Download the data Sheet from their web page.

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Zemax is supplied with the glass catalogs of the major manufacturers

(which are built-in to Zemax), but there are times when you still need to add

your own glass data. There are several methods to do this in Zemax.

Zemax Table Glass file is a simple ASCII list.

Open notepad save the data

as shown.

Note

Density : is in gram/cc.

1st column : WL in um

2nd column: index of refraction.

Filename:

MYGLASS.ZTG

Path:

C:\<ZemaxFolder>\Glasscat

In my computer C:\Users\Bingul\Documents\Zemax\Glasscat

Example2: How To Enter Glass Data at Specific Wavelengths

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In the lens data editor, write the file name and its extension

in the Glass (Material) column as below.

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In the Libraries Tab, Click on Len Catalog

Select THORLABS as a Vendor

Example 3: How to add a lens from the Lens Catalog

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Layout of LBF254-050 EFL=50.06 EPD=22.86

Exercise: Look at the abberrations for 587 nm

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Test plate fitting is a Zemax utility to redesign a lens to fit

Vendors (company) tooling.

Primary reason is to reduce fabrication cost and delivery time,

as each test plate has to be manufactured as a pair and that

involves cost and time.

Example 4: Test Plate Fitting

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Consider we design a bi-convex lens.

EFL = +300 mm Glass = N-BK7

λ = Fraunhoffer d line (587 nm, n = 1.5168)

EPD = 25.4 mm ct = 5 mm

Determine the radii of curvatures of the lens such that parallel incident light

has minimum spherical aberration.

SOLUTION:

Applying Coddington formulae yield:

For these radii EFFL = 300.299 mm in Zemax.

1300

300

oi

oi

ss

ssP

0.73972

)1(2 2

P

n

n

mm 178.2381

)1(21

nfR

mm 1191.2251

)1(22

nfR

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First make Radii variable.

Then, In the Optimize Tab, click on Test Plate Fitting

Select file (company) name then click OK

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Zemax will show you Test Plate Fit Results as follows:

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Best values are inserted in LDE automatically by Zemax.

Note that,

you may check if optical performance before and after test plate fitting

(e.g. See Ray Fan and Spot Diagrams)!

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A comparison of the designed lens and best suggested lens.

PARAMETER OLD NEW

----------- --------- ---------

Radii 178.238 178.562

-1191.225 -1198.499

Effl 300.299 301.010

GEO Radius 23.811 23.699

RMS Radius 14.701 14.632

SPHA 0.002 0.002