Authored By: Sanjay Gangadhara

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File extensions listed categorically

Updated 09 October 2009, to adhere to the directory structure for user files that was introduced with the 12 October 2009 release of Zemax.

This article is also available in Japanese.

Designing a lens system in Zemax involves using many pieces of information, which in general are distributed in a variety of files and file types. Here, we provide a simple listing for all of the various file types supported by Zemax, sorted by category. An alphabetical listing of the file types - along with their necessary location - is also provided, starting on the next page of this article.

General

CFG: Zemax configuration file, which contains saved analysis settings
SES: Zemax session file, which contains information on open windows and their settings
ZAR: Zemax archive file, which contains all of the files associated with a given lens design
ZMX: Zemax lens file, which contains all design specifications

Input data

AGF: ASCII glass catalog file
BGF: Binary glass catalog file
BSDF: Contains measured scattering distribution (BSDF) data to be used for modeling surface scattering
DAT: Contains ABg scattering distribution data to be used for modeling surface scattering
IND: Input n(l) data file that will be fit using the Glass Fitting Tool
GRD: Used to define GRADIUM^TM profile data
TID: Input n(l,T) data file that will be fit using the Glass Fitting Tool
TPD: Test plate data file
ZMF: Lens catalog data file
ZTG: Zemax table glass file

Surface data

DAT: Contains data used to model the Grid Sag surface in sequential mode
DAT: Contains data used to model the Grid Phase surface in sequential mode
DAT: Contains data that can be imported into the Extra Data Editor for modeling a surface

Object data

TOB: Contains data used to model a Tabulated Faceted Radial object
TOB: Contains data used to model a Tabulated Faceted Toroidal object

User-defined data

C: C language source code files
DLL: Dynamic Link Library file, to model user-defined surfaces, objects, scattering distributions, etc.
POB: Contains data used to model a user-defined Polygon object
UDA: Contains data used to model a user-defined aperture (sequential and NSC)

Imported data

F3D: OptiWave file containing electric field data for an input beam
INT: Contains interferometric measurement data used to model a surface (Zernike, Grid)

CAD-related

IGES, IGS: Initial Graphics Exchange Specification file
SAT: Standard ACIS Text file
STEP, STP: Standard for the Exchange of Product model data file
STL: Stereolithography file
ZEN: Used to specify face number assignments on a CAD file
ZOF: Zemax object format file

NSC Sources

DAT: Used to define a Source File object
IES: Used to define a Source IESNA object
LDT: Used to define a EULUMDAT source object
SPC: Used to define a source spectrum

NSC Objects

DAT: Contains default coating/scatter profiles for NSC objects

NSC Ray Trace

ZRD: Ray database file, containing information on ray positions, trajectories, etc.

Graphics

ANN: Annotation files (binary), used to store user defined annotations for Zemax graphics
ELE: Settings file for the Zemax Element Drawing
NOT: Element Drawing note file.

Image Analysis

BIM: Binary image file, used by the Image Simulation and associated features
BMP: Bitmap image file, used by the Image Simulation and associated features
EMF: Enhanced metafile, used by Metafile graphics
IMA: ASCII or binary image file, used by the Image Simulation and associated features
JPG: Joint Photographic Experts Group image file, used by the Image Simulation and associated features

Polarization

DAT: ASCII coating file
ZEC: Encrypted coating file

POP

ZBF: Zemax beam file, which stores beam electric field data
ZMM: Zemax multi-mode file, used to define a multi-mode POP beam

Optimization

MF: Contains saved settings from the Merit Function Editor

Tolerancing

TOL: Contains saved settings from the Tolerance Data Editor
TOP: Contains saved settings from the Tolerance settings dialog box
TSC: Tolerance script file, used to run scripted analysis during tolerancing
“”: Files that contain user-defined statistics to use in tolerancing can have any extension

Macros

ZPL: An ASCII file containing script commands in the Zemax Programming Language

File extensions listed alphabetically, part I
Here is a list of the extensions used by all of the files that are a part of Zemax, sorted alphabetically. The necessary location for each file type is also provided.

Extension	Description	Location
AGF	ASCII Glass Format. These are ASCII files which contain the data for glass catalogs. An ASCII format is used so that additional data may be incorporated  in future releases of Zemax.	These files should be located in the directory {user}\Documents\Zemax\Glasscat\, or in the Glass Path provided in the File > Preferences > Folders menu.
ANN	Annotations files. These binary files store user defined annotations for Zemax graphics.	These files may be located in any directory.
BGF	Binary Glass Format. To accelerate the loading of AGF files, Zemax converts AGF files to BGF, which are the version specific binary images of the glass catalogs.	These files will automatically be generated by Zemax from the AGF files. The location of these files is the same as for the AGF files.
BIM	Binary Image File. These files are used to define an extended source for the Image Simulation and associated image analysis features.	The input files should be located in the directory {user}\Documents\Zemax\IMAFiles\.
BMP	Bitmap Image File. These files are used to define an extended source for the Image Simulation and associated image analysis features. They can also serve as a reference for the Focault Analysis, or can be used with the non-sequential Slide object.	The input files should be located in the directory {user}\Documents\Zemax\IMAFiles\.
BSDF	Bi-Directional Scatter Distribution Function file. These files contain tabulated BSDF values which represent measured data for  the angular distribution of scattering from a particular surface (see the article entitled "How to Use Tabular BSDF Data to Define the Surface Scattering Distribution" for more details).	These files should be located in the directory {user}\Documents\Zemax\Miscellaneous\.
C	C language source code files (i.e. for creating user-defined surfaces, objects, etc.).	These files may be located in any directory.
CFG	Configuration files. Zemax.CFG is the main configuration file which describes the user-selected options on the environment dialog box. There are numerous other files that may be present which end in CFG;  for example, RAY.CFG contains the user-defined defaults for the Ray Fan plot.	The configuration files associated with general analysis features, such as RAY.CFG (Ray Fan plot) or POP.CFG (Physical Optics Propagation) are located in the directory {user}\Documents\Zemax\Configs\. Lens-specific configuration files are located in the same directory as the corresponding lens (.ZMX) file.
DAT	DAT files are used for a variety of applications in Zemax. They are: (1) ASCII files which contain sag data used to model a surface via the Grid Sag surface. (2) ASCII files which contain phase data used to model a surface via the Grid Phase surface. (3) ASCII files which contain data for input into the Extra Data Editor, for those surfaces in which this editor is needed to define the full range of surface parameters. (4) ASCII or binary files which contain data used to model a non-sequential source via the Source File object. (5) ASCII files which contain coating data for use in sequential and non-sequential mode. (6) ASCII files which contain ABg scatter data. (7) ASCII files which contain coating/scatter profiles to apply to various faces of non-sequential objects.	For the first 3 applications shown to the left, these files may be located in any directory. For the Source File object, the input files should be located in the directory {user}\Documents\Zemax\Objects\Sources\Source Files\,  or in the \Sources\Source Files\ directory for the Objects Path provided in the File > Preferences > Folders menu. The input files which contain coating data should be located in the directory {user}\Documents\Zemax\Coatings, or in the Coating path provided in the File > Preferences > Folders menu. The ABg scatter data files should be located in the directory {user}\Documents\Zemax\ABg_Data. The coating/scatter profile data files should be located in the directory {user}\Documents\Zemax\Profiles\.
DLL	Dynamic Link Library files. These files are externally compiled programs linked into Zemax at run time. They can be used to model user-defined surfaces, objects, scattering distributions, etc.	The location for these files is application-dependent. For example, the files for user-defined surfaces should be located in the directory {Install directory}\Zemax\DLL\Surfaces\, whereas the files for user-defined objects should be located in the directory {Install directory}\Zemax\DLL\Objects\.
ELE	Element drawing settings files. These files contain saved settings for the Zemax Element Drawing feature, that can be used to define the settings of this feature in any lens file.	The input files may be located in any directory.
EMF	Enchanced Metafile. These files contain graphics exported from Zemax in the Windows Metafile format.	These files may be located in any directory.
F3D	OptiWave F3D files. These files contain electric field data for a beam generated by a fiber or waveguide, as calculated by the OptiBPM or OptiFiber codes (see the article entitled "How to Get Real Waveguide Mode Data into Zemax" for more details). The files can be converted into the Zemax Beam File (ZBF) format for use with the Physical Optics Propagation tool.	The input F3D files may be located in any directory. The converted ZBF files must be located in the directory {user}\Documents\Zemax\POP\Beamfiles\ if they are going to be used with the Physical Optics Propagation tool.
GRD	GRADIUMTM profile data files. These files contain refractive index profile data for stock gradient index blanks provided by LightPath Technologies, Inc.	These files should be located in the directory {user}\Documents\Zemax\Glasscat\, or in the Glass Path provided in the File > Preferences > Folders menu.
IES	Souce IESNA files. These are source files that contain measured photometry data for a real lamp, formatted according to the Illumination Engineering Society of North America(IESNA) Standard File Format for Electronic Transfer of Photometric Data. These files are used with the Source IESNA File object in non-sequential mode.	The input files should be located in the directory {user}\Documents\Zemax\Objects\Sources\IESNA\, or in the \Sources\IESNA\ directory for the Objects Path provided in the File > Preferences > Folders menu.

File extensions listed alphabetically, part II

Extension	Description	Location
IMA	Image File. These files are used to define an extended source for the Image Simulation and associated image analysis features. These files may be ASCII or binary.	The input files should be located in the directory {user}\Documents\Zemax\IMAFiles\.
IGES, IGS	IGS Initial Graphics Exchange Specification file. These files contain CAD representations of system components, which may be used to model objects in non-sequential mode.	The input files should be located in the directory {user}\Documents\Zemax\Objects\CAD Files\, or in the \CAD Files\ directory for the Objects Path provided in the File > Preferences > Folders menu.
IND	Refractive index profile data file. These ASCII files contain index vs. wavelength data for a glass, to be fit to one of the dispersion formulas supported by Zemax (see the article entitled "Fitting Index Data in Zemax" for more details).	The input files should be located in the directory {user}\Documents\Zemax\Glasscat\, or in the Glass Path provided in the File > Preferences > Folders menu.
INT	Interferometric measurement data file. These files contain surface measurement data obtained with an interferometer. These data may be used to model a surface in Zemax  by converting the measured data into either: (1) Zernike coefficients to be used with the Zernike Standard or Zernike Fringe surfaces, or (2) Tabular data to be used with the Grid Sag or Grid Phase surface.	The input files may be located in any directory.
JPG	Joint Photographic Experts Group Image File. These files are used to define an extended source for the Image Simulation and associated image analysis features. They can also serve as a reference for the Focault Analysis, or can be used with the non-sequential Slide object.	The input files should be located in the directory {user}\Documents\Zemax\IMAFiles\.
LDT	Source EULUMDAT files. These are source files that contain measured photometry data for a real lamp, provided in a common format known as the EULUMDAT format. These files are used with the Source EULUMDAT file object in non-sequential mode.	The input files should be located in the folder {user}\Documents\Zemax\Objects\Sources\EULUMDAT\, or in the \Sources\EULUMDAT\ directory for the Objects path provided in the File > Preferences > Folders menu.
MF	Merit Function file. These files contain the full list of operands, targets, and weights for a saved merit function. The files can be used, e.g., to define the same custom merit function for different lens files, or to define different merit functions for tolerance analysis.	The input files may be located in any directory, although the default path is {user}\Documents\Zemax\MeritFunction\.
NOT	Element drawing note file. These ASCII files contain the notes to be appended to the notes section of the Zemax Element Drawing feature, to be used in any lens file.	The input files should be located in the directory {user}\Documents\Zemax\Miscellaneous\.
POB	Polygon Object file. These ASCII files are used to define polygon objects in non-sequential mode. The objects are based on a collection of 3D triangles whose vertices are placed in the ASCII file. The objects may be open polygon surfaces or closed polygon volumes.	The input files should be located in the directory {user}\Documents\Zemax\Objects\Polygon Objects\, or in the \Polygon Objects\ directory for the Objects Path provided in the File > Preferences > Folders menu.
SAT	Standard ACIS Text file. These files contain CAD representations of system components, which may be used to model objects in non-sequential mode.	The input files should be located in the directory {user}\Documents\Zemax\Objects\CAD Files\, or in the \CAD Files\ directory for the Objects Path provided in the File > Preferences > Folders menu.
SES	Session files. These files define the display configuration and open windows and settings for the corresponding lens (.ZMX) file. If the .SES file is present in the same directory as the corresponding lens file, then when you open the lens file all of the analysis windows and editors appear in the exact same location as they were when the file was last saved, and all of the open analysis windows use the same settings as when the file was last saved.	These files should be located in the same directory as the corresponding lens (.ZMX) file.
SPC	Spectrum Source file. These ASCII files contain spectral data (i.e. wavelength and weight) for a source to be modeled in non-sequential mode. This data is similar to the data input for the Wavelength Data dialog box, but allows up to 100 wavelengths to be defined for a single source (the Wavelength Data dialog box only allows 24 wavelengths per configuration), and different files to be used for different sources.	The input files should be located in the directory {user}\Documents\Zemax\Objects\Sources\Spectrum Files\, or in the \Sources\Spectrum Files\ directory for the Objects Path provided in the File > Preferences > Folders menu.
STEP, STP	Standard for the Exchange of Product model data file. These files contain CAD representations of system components, which may be used to model objects in non- sequential mode.	The input files should be located in the directory {user}\Documents\Zemax\Objects\CAD Files\, or in the \CAD Files\ directory for the Objects Path provided in the File > Preferences > Folders menu.
STL	Stereolithography file. These files contain CAD representations of system components, in both ASCII and binary formats. These files may be used to model CAD objects in non-sequential mode.	The input files should be located in the directory {user}\Documents\Zemax\Objects\CAD Files\, or in the \CAD Files\ directory for the Objects Path provided in the File > Preferences > Folders menu.
TID	Refractive index profile data file. These ASCII files contain index vs. wavelength and temperature data for a glass, to be fit to the Zemax thermal model and to one of the dispersion formulas supported by Zemax (see the article entitled "How to Fit Temperature-Dependent Index Data to the Zemax Thermal Model" for more details).	The input files should be located in the directory {user}\Documents\Zemax\Glasscat\, or in the Glass Path provided in the File > Preferences > Folders menu.
TOB	Tabulated object data file. These ASCII files contain data used to generate a Tabulated Faceted Radial object or a Tabulated Faceted Toroidal object in non-sequential mode.	The input files should be located in the directory {user}\Documents\Zemax\Objects\Tabulated Objects\, or in the \Tabulated Objects\ directory for the Objects Path provided in the File > Preferences > Folders menu.

File extensions listed alphabetically, part III

Extension	Description	Location
TOL	Tolerance file. These files contain the full list of operands and perturbation values (min and max) for a saved Tolerance Data editor. These files can be used, e.g., to define the same custom tolerances for different lens files.	The input files may be located in any directory, although the default path is {user}\Documents\Zemax\Tolerance.
TOP	Tolerance settings file. These files contain the saved settings from the settings dialog box for the Tolerancing tool. These files can be used, e.g., to define the same tolerance analysis settings for different lens files, or to define the tolerance analysis settings to be used with the TOLR optimization operand (see the article entitled "How To Optimize for As-Built Performance" for more details).	For general tolerance analysis, the input files may be located in any directory, although the default path is {user}\Documents\Zemax\Tolerance. For use with the TOLR operand, the input files should be located in the directory {user}\Documents\Zemax\Configs\.
TPD	Test Plate data files. These ASCII files contain test plate lists supplied by various optical fabricators, for use with the Test Plate Fitting tool.	The input files should be located in the directory {user}\Documents\Zemax\Testplate\.
TSC	Tolerance script file. These ASCII files contain script commands which allow a procedure to be defined for evaluating the performance of a lens during tolerancing. This is useful for simulating complex lens alignment, or for monitoring and reporting specific system values during tolerance analysis.	The input files should be located in the directory {user}\Documents\Zemax\Tolerance.
UDA	User Defined Aperture file. These ASCII files contain commands used to define an arbitrary aperture (or obscuration) shape. Shapes may be composed of a series of line segments, arcs, circles, polygons and rectangles, and may be closed in a simple or complex way. Nesting of shapes is allowed as well.	The input files should be located in the directory {user}\Documents\Zemax\Objects\Apertures\, or in the \Apertures\ directory for the Objects Path provided in the File > Preferences > Folders menu.
ZAR	Zemax Archive file. These files contain all of the files associated with a lens design in a single, compressed format. This is useful for keeping track of the files associated with a given lens design, and for sending that information to others in a compact manner.	These files may be located in any directory. Upon restoration of the archive file, the associated files (i.e. glass catalogs, coatings, CAD, etc.) will be sent to the appropriate directories.
ZBF	Zemax Beam file. These files contain beam electric field data used with the Physical Optics Propagation (POP) analysis feature. User-defined files, which may be ASCII or binary, are used to specify the initial POP beam. Zemax can also generate binary files which contain the electric field data for the beam at any surface along the propagation path.	The input files should be located in the directory {user}\Documents\Zemax\POP\BEAMFILES\.
ZEC	Zemax Encrypted Coating file. These files contain encrypted coating data, which allow the user to specify a coating in a lens file without  having to know the detailed coating information. This is useful for users who wish to distribute lens files that contain coatings but without having to provide any proprietary coating information.	The input files should be located in the directory {user}\Documents\Zemax\Coatings\, or in the Coating Path provided in the File > Preferences > Folders menu.
ZEN	Zemax Face Number file. These files contain the face number assignments for a CAD object imported into non-sequential mode.	These files are generated by Zemax once the CAD object is imported into non-sequential mode. The files are thus located in the same directory as the parent CAD objects.
ZMF	Zemax Lens Catalog file. These files contain compilations of ZMX format files which are used to define lenses in the stock lens catalogs.	The input files should be located in the directory {user}\Documents\Zemax\Stockcat\.
ZMM	Zemax Multi Mode file. These ASCII files are used to define a multimode beam for use with the Physical Optics Propagation analysis feature. The beam is created from a coherent or incoherent sum of other beams.	The input files should be located in the directory {user}\Documents\Zemax\POP\BEAMFILES\.
ZMX	Zemax lens file. These ASCII files contain the complete description of the lens, including apertures, wavelengths, prescription data and the merit function.	These files may be located in any directory.
ZOF	Zemax Object Format file. These files contain the representation of a CAD object that is used by Zemax internally. Zemax will automatically convert any CAD objects that are imported into non-sequential mode as IGES, STEP, or SAT files into a corresponding ZOF file.	These files are located in the same directory as the parent CAD objects.
ZPL	Zemax Programming Language files. These ASCII files contain macro commands which can be used to run Zemax in a script mode. This is useful for automating tasks in a lens design, generating custom plots, etc.	The input files should be located in the directory {user}\Documents\Zemax\Macros\, or in the ZPL Path provided in the File > Preferences > Folders menu.
ZRD	Zemax Ray Database file. These binary files contain complete information (such as position that the ray hits the object, direction of the ray after refraction, polarization state of the ray, etc.) for each ray that is traced in a non-sequential system. Filter strings may then be used to isolate specific rays in the database (see the article entitled "How to Identify Specify Rays using Filter Strings" for more details).	These files should be located in the same directory as the corresponding lens (.ZMX) file.
ZTG	Zemax Table Glass file. These ASCII files contain tabulated data for the refractive index and transmission of a glass vs. wavelength. This is useful for modeling glasses when the index data cannot be well fit to one of the dispersion models supported by Zemax.	The input files should be located in the directory {user}\Documents\Zemax\GlassCat, or in the Glass Path provided in the File > Preferences > Folders menu.