Optical Design Exchange (ODX)

Optical Design Exchange (ODX) is a feature and file format used to transfer optical system data from Ansys Zemax OpticStudio into Speos, Speos for NX (26R1) or Speos for Creo (26R1 SP3). It enables seamless import of optical designs, including geometries, optical properties, sensors, and sources for advanced multiphysics and system-level stray light analysis workflows.

Authored by: Tobias Lauinger, Mina Nazari, Zach Derocher, Aubry Grossetete

download example (.zip)

Introduction

Definition and Purpose:

The ODX feature acts as a component within Speos that links imported optical geometries, such as lenses, stops, and mirror surfaces, to their corresponding optical properties and imports sensors and field sources as defined in Zemax OpticStudio. For CPU simulations, ODX uses ray propagation that relies on analytical descriptions of optical surfaces, ensuring that lens shapes are preserved without the approximations associated with standard CAD exports. This enables users to accurately model and run nonsequential simulations of complex optical imaging and non-imaging systems within Speos. In the design and development of optomechanical systems, evaluating stray light and assessing performance metrics requires consideration of both the optical component geometry and the opto-mechanical components that constrain and influence system performance.

Typical Workflow

1. [OpticStudio] Design Creation: Optical systems are designed and optimized in Ansys Zemax OpticStudio, including lens geometry, coatings, and sensor definitions.
2. [OpticStudio] Export: The optical design is exported as an .odx file, which contains all relevant data for optical simulation.
3. [Speos] Import: The .odx file is imported as a Speos component into Speos, where based on the Zemax model, the lens geometries, materials, coatings, field sources and sensors are automatically created and applied in the model.
4. [Speos] Optomechanical Integration and Modification: Imported optical geometries can be used as references for designing lens edges, surrounding mechanical parts or for further modification within Speos, PTC Creo or Siemens NX, the CAD platform in which Speos is integrated.
5. [Speos] Simulation: Users can then perform non sequential optical analyses (such as stray light, photometric and radiometric simulations) within Speos, leveraging the imported data for efficient and accurate analysis.

Supported Surface and Object Types

Optical systems in both sequential (SEQ) and nonsequential (NSC) modes of OpticStudio are supported. We recommend using the same latest release version of OpticStudio and Speos to ensure compatibility with the .odx file version in both tools.

List of supported surfaces and objects (Release 2026 R1):

Important Notes and Best Practices

• As of version 2025 R2.1, a coordinate break can be used outside and inside geometries.
• As of version 2025 R2.4, to support simple prisms (max. 2 optical surfaces), tolerance optical systems and internal coordinate breaks, a new geometry type “Solid Body” has been introduced. A solid body contains:
  • Two optical surfaces, each with its own axis system, ensure correct relative orientation.
  • A list of surface bodies and matching axis systems (one per surface)
• Global Coordinate Reference Surface: The selected surface in OpticStudio determines the global coordinate system origin location and orientation. This reference surface’s position is also used in Speos as the origin axis system for the ODX component.
• Ansys Best Practice: When working with optical systems and their integration in the 3D environment in Speos, it is recommended to define the reference axis system at the center of the imager. This convention is consistent with standard Speos camera sensor definitions.
• To verify the position of the imported .odx component, select the Irradiance sensor axis system in the structure tree. Then press Move + Spacebar to display the XYZ coordinates of the axis system.

In Speos, you can move the entire ODX component or individual geometry objects after importing. However, if the .odx component is recomputed, the positions and modifications of these elements will be reset.

Apertures

Allowed front/back aperture combinations:

• Circular – Circular (Lenses, Solids)
• Elliptical – Elliptical (Lenses, Solids)
• Rectangular – Rectangular (Lenses, Solids)
• Elliptical - Circular (Solids)
• Circular - Elliptical

Note:

• Circular apertures with minimum radius are not supported by systems with coordinate breaks inside geometries.
• Different aperture dimensions and decenters between the two surfaces are permitted.

Ray-tracing Accuracy / Meshing / Analytical Intersector

• Local Meshing: Speos relies on meshing 3D geometries for ray propagation. A “Local Meshing” is automatically created to represent the mesh generated for the Optical Design Exchange (ODX) feature. 

  

• Analytical Intersector (since release 2025 R2.4): While the default local meshing is suited for non-imaging systems, this method typically lacks the extreme precision of the analytical surface descriptions found in Ansys Zemax OpticStudio. To compensate, users often had to fine-tune meshing parameters to ensure accuracy. Since version 2025 R2.4 Speos now bridges this gap by utilizing analytical surface descriptions directly from imported ODX geometries. Analytical surface descriptions are primarily associated with specific optical faces.

  

  This allows Speos to calculate exact ray-surface intersections (Analytical Intersector) rather than relying solely on a discretized mesh.

  The Speos HTML Report states the intersection method used for each lens face:

  

• High-precision analytical intersector was used for front and back face of Lens_1-2.
• Any face lacking analytical information will default to standard local odx meshing for ray propagation (for example chip zones or lens edges).

Note: The Analytical Intersector is currently supported only for CPU-based simulations. GPU simulations rely on the local mesh representation.

Optical Properties

In Ansys Zemax OpticStudio, optical properties must be defined for each lens in the optical system.
These optical properties, Materials (Volume Optical Properties) and Coatings (Surface Optical Properties), are the only properties considered by Speos after .odx import.
In Speos, you can modify optical properties even after importing an optical system from an .odx file. This allows you to explore alternatives such as different coatings or material definitions without needing to re-export the optical design from Ansys Zemax OpticStudio.

Important change as of Speos 2025 R2:

• The imported optical property information is created as an editable Material feature in Speos.
• In previous Speos version, optical properties were read‑only and embedded inside the child's geometries under the Optical Design Exchange (ODX) feature, limiting flexibility.

Standard Glass Materials

OpticStudio provides an open glass catalog.
When exporting an .odx file, the following material data are included (and transferred into a *.ZemaxMaterial file used by Speos):

• Glass catalog and reference
• Dispersion formula used
• Dispersion coefficients
• Minimum and maximum supported wavelengths
• Spectral absorption

Mirror Substrate (Material Behavior)

If a lens is defined with Mirror Substrate = Flat or Curved, its Volume Optical Property becomes Opaque when imported into Speos.

Table Glass materials

Release 2025R2 SP4, enables OpticStudio (Zemax) Table Glass materials (ZTG files) to be exported through Optical Design Exchange (ODX) and interpreted identically in Speos. This allows designs imported from 3rd party optical design tools to be exported to Speos.
Table Glass materials (.ztg) define material properties per wavelength:

• Refractive index
• Transmissivity
• Corresponding thickness

When exported to .odx, Table Glass data are embedded in an encrypted *.ZTG.ZemaxMaterial file containing:

• Wavelengths (nm)
• Refractive index values per wavelength
• Absorption coefficients (mm⁻¹), computed from transmission + thickness

The details and format of the table glass materials are described in this article:
How to enter glass data at specific wavelengths
 

Coating (Surface Optical Properties)

The .odx export includes 600 uniform spectral sampling data points cover reflection, transmission, and absorption as functions of:

• Incident angle
• Wavelength

Important Note: 
Speos performs linear interpolation between the 600 samples. If coating behavior changes significantly between sample points, wavelength‑specific variations may be lost.
→ Recommended: oversample or refine coating data before exporting to .odx.

Mirror Substrate (Coating Behavior)

When Mirror Substrate = None

• Surface Optical Property = MIRROR coating
• No transmission included

When Mirror Substrate = Flat or Curved

• Front face: MIRROR coating as defined in OpticStudio
• Edge & Back faces: default 0% reflectance

Sensors

In Ansys Zemax OpticStudio, you must define the sensor used in the optical system:

• Sequential mode: Sensors are defined based on the size of the image surface.
• Non‑sequential mode: Sensors are defined using the size and pixel count of a Detector Rectangle object.

In Speos the Imager is represented by an Irradiance sensor. The Irradiance sensor is created under the Sensors section of the Simulation panel.

Sources

Only Sources defined in Zemax Sequential mode can be exported to the *.odx file. The sources are defined by fields, the object distance and if the system uses ray aiming the STOP surface.

When sources are imported into Speos both types are represented by an emissive surface source with an elliptical shape. Generally, sources in Speos are represented by:

Elliptical Source – For object at infinite distance, with rays being emitted in a collimated beam parallel to the surface. The z-axis of the source is determined by the chief ray. The elliptical source size is determined by the pupil dimensions.

Point Source – For the object at a finite distance, with z-axis defined by the chief ray, and emission cone defined by pupil solid angle. Size is represented by the smallest elliptical shape that can be represented in Speos (radius 0.01mm).

All these source support geometries share a single Material feature with:

• Volume optical properties set to Optic (n=1) to account for an air material or a *.ZemaxMaterial file corresponding to an air material.
• Surface properties set to Optical polished

Recommended Stray light Analysis Workflow for Speos

1. Define and optimize the optical system in Ansys Zemax OpticStudio, including coatings, apertures, and other optical design parameters. 
2. Export the optical design from Ansys Zemax OpticStudio as an .odx file.
3. Import the .odx optical system into Ansys Speos.
4. Add any required opto-mechanical and stray-light-relevant geometries, such as:
   • Complex lens edge geometries (if required for stray light analysis)
   • Housing
   • Lens barrels
   • Mounting structures
   • Spacers
5. Run the simulation and analyze the results.
6. Use the simulation results to refine the optical and mechanical design as needed.

Note: As an initial step, an .odx file can be generated from the cellphone camera lens design in Zemax OpticStudio. After importing the optical system into Speos, additional geometric and opto-mechanical components can be incorporated to create a realistic stray-light model. In this example, detailed lens-edge geometries are created in a CAD tool and merged with the imported optical system. The completed assembly can then be used for stray-light analysis. Finally, feedback from the simulation can guide design iterations related to the mechanical design, lens-edge geometry, coatings, and other optical system parameters.

Step 1: Export the .odx File from Zemax OpticStudio (Optional)

1. Download the attachment from this article.
2. Open the project "710_reoptimized_MTF_materials_QType_wAR_SR.zmx" (located in “\ZOS\”) in Ansys Zemax OpticStudio
3. Note: This lens system is optimized for ghost and stray light analysis and includes anti-reflective coatings on the most critical lens surfaces.

4. Click on File--> “Export Optical Design to Speos”

   

5. The generated .odx file and export log file are saved in the project directory.

   Optional: Specify a custom filename and output directory before exporting.

6. A pop-up window confirms the exports have been completed successfully.

Step 2: Import *.odx optical system into Speos

1. Start Ansys Speos and open the “Cellphone_camera_v1.scdocx “ project (located in “\Speos\”).

   Note: The project includes a predefined Intensity Sensor covering the hemisphere in front of the camera for an initial Detector FOV Analysis.
2. In the Light Simulation ribbon, click Optical Design Exchange in the Components group.
3. An Optical Design Exchange Component is created in the Simulation panel.
4. In the Definition panel:
   • Keep the default axis system references.

   • Browse to the exported .odx file.

     

5. Click Compute to import the optical design.

   During computation, Speos automatically creates:

   • Lens geometries with associated optical properties
   • Aperture stop geometries
   • Field sources
   • Irradiance sensor
   • Local meshing for the imported geometries and sources
6. Verify that the sensor is located at the global coordinate system origin.

The imported optical design definitions are read-only to ensure consistency with the original optical design. The resulting geometries can still be modified using SpaceClaim modeling tools if additional geometry modification is required (see Step 3).

Note

• Dimensions are imported in millimeters
• Wavelengths in nanometers.
• A radius value of zero represents an infinite radius.

Step 3: Add and combine Lens Edge Geometries

The ODX workflow imports the optical system definition required for accurate optical simulation, including optical surfaces, materials, coatings, and apertures. Additional geometrical details, such as detailed lens-edge and opto-mechanical geometries, may need to be created or imported separately to support realistic stray-light analysis.

The article Designing Cell-phone Camera Lenses Part 2: Optomechanical Packaging describes the creation and import of lens edge geometries. In the following steps, the optical surfaces and lens edge geometries are combined into lens solids while preserving surface accuracy, material assignments, and coating information.

Note: Optical diopters (lens surfaces imported through the .odx file) typically represent optically polished surfaces, whereas lens edges are generally not polished. For simplicity, the lens edges are treated as polished surfaces in this workflow. If required, a face optical property can be assigned to the lens edge surfaces to overwrite the default polished surface finish and define a more realistic scattering behavior.

The dataset includes cylindrical edge solids that connect to the imported lenses.

Before combining the optical surfaces with the lens edge geometries, verify that:

• The outer lens edges and inner cylindrical edge surfaces are tangent.
• No gaps exist between the optical surfaces and the edge geometries.
• The edge geometry fully encloses the optical surfaces.
• The resulting solid forms a watertight body suitable for subsequent Boolean operations and material assignment.

Combine lens bodies with the edges:

1. In the Design tab, click Combine.
2. Select the lens that should be merged into a single body.
3. In the Combine tool options choose Add and activate “Merge when done” as the operation type.
4. Select the lens edge.
5. Verify that the selected geometries are now listed as a single lens body in the model tree.

Note: The analytical surface description (analytical intersector) remains valid as long as the optical surfaces themselves are not modified.

Step 4: Add Opto-Mechanical Components to the simulation

To accurately reproduce all stray light paths of the system, include the surrounding mechanical environment.

• Spacer rings
• Sensor package
• Camera housing
• Lens barrel

The geometries tab of the Detector FOV Analysis simulation contains all optical and mechanical geometries (16 geometries):

• Mechanical geometry imported from the camera assembly (for example, the barrel, baffles, sensor housing, and sensor).
• Optical geometry imported through the Optical Design Exchange (for example, lenses and the optical stop).

Verify that all 16 geometries are added to the simulations.

Step 5: Run the simulation and analyse the results

To verify that the simulation is configured correctly, perform the following system-level stray light analysis. 

1. Save the project and run the "Detector FOV Analysis" on the CPU (approximately 20 minutes using 20 CPU cores).
2. Open the Detector FOV Analysis.Intensity.lpf result.
3. To visualize all nominal imaging ray paths, activate only the first sequence in the Virtual Lighting Controller.
4. To visualize all stray-light ray paths, activate all sequences and then unselect the first sequence.
5. For each configuration, you can enable the ray animation feature to gain a better understanding of the system's behavior.

ODX Workflow in Speos for NX

Recommended Training: The Optical Design Exchange (ODX) workflow is now available in Ansys Speos for NX 26R1. This training introduces the ODX workflow, including:

• Export and import of optical systems
• NX-based parameterization of optical designs
• Tolerance analysis for imaging systems

This course Optical Design Exchange in Ansys Speos Software for NX (Tutorial) (available on Ansys Learning HUB) is recommended for users who want to integrate optical design workflows more efficiently within the Speos for NX environment.

ODX Workflow in Speos for Creo

Recommended Training: The Optical Design Exchange (ODX) workflow is available in Speos for Creo 26R1 SP3. We recommend reviewing the following training video before using ODX. The video covers:

• Exporting optical systems from Zemax OpticStudio
• Importing optical systems into Speos using ODX
• Managing optical geometries, materials, sources, and sensors
• Best practices and workflow recommendations

Link to the video: Speos for Creo | ODX & Straylight Analysis

Known Limitations

• Analytical Intersector is CPU-only. GPU simulations rely on the meshed representation of the ODX geometry (refine local meshing if necessary).

• Zemax Black Box components cannot be exported.

• Only Sequential Mode sources are exported. Sources defined in Zemax Non-Sequential Mode are not transferred through ODX.

• Unsupported geometries require a workaround. Unsupported objects must either be manually exported as CAD or transferred through the ODX Hybrid Importer workflow.
  

Additional resources

Stray Light Analysis Overview – Ansys Optics

Stray Light Analysis – Smartphone Camera – Ansys Optics

Automating system-level stray light analysis and optical noise reduction with Ansys Optics – Ansys Optics

Point Source Transmittance – Ansys Optics

SpaceClaim User's Guide: Scripting