This article shows how suppliers and Original Equipment Manufacturers (OEM) can exchange encrypted optical models, also called black box models, from optical component design in Ansys Zemax OpticStudio to system analysis in Ansys Speos.
Overview
There are two types of black box models which can be transferred from Ansys Zemax OpticStudio to Ansys Speos between supplier and OEM:
- Optical Reduced Order Model for camera application: This method does not transfer the optical system itself but uses a reduced order model instead. This model considers the main path of the light through the optical system.
- Optical Design Exchange for all applications (camera, HUD …): This method transfers the optical system and its optical properties. This model considers all the light paths through the system
Optical Reduced Order Model | Optical Design Exchange | |
Advantage | Faster calculation | Considers all the optical paths |
Limitation | Considers only the main optical path | Slower calculation |
Type of Analysis | Optical System Performance Analysis | Stray light and Lens Flare Analysis |
Application | Camera Only | Camera, HUD, Collimator ... |
- Optical Reduced Order Model (not covered in this article)
Optical ROM facilitates rapid yet accurate camera simulations. By reproducing key real camera lens properties, it enables camera performance validation, generating photometric results in terms of the irradiance captured in front of sensor without compromising lens manufacturer intellectual property.
The function “Export Reduced Order Model to Speos” is available in Ansys Zemax OpticStudio and generates an encrypted *.OPTDistortion file. This contains the ROM of the lens system and is used for camera definition in Ansys Speos.
More information about how to generate the Optical ROM are available here: Getting started with Speos Camera Sensor and running an example – Ansys Optics
- Optical Full Model or Opto-Mechanical Full Model
In this article, we focus on how to export and import an encrypted Optical Full Model or Opto-Mechanical Full Model from Ansys Zemax OpticStudio to Ansys Speos. In order to exchange black box full model, the supplier would:
- Export the optical design as an *.odx file from Ansys Zemax OpticStudio
- Import the *.odx file into Ansys Speos by using Optical Design Exchange feature
- Generate a *.SPEOSLightBox file by creating a Light Box Export, with black box option activated, containing the optical system from .odx file and potential mechanical components
Then, the OEM would:
- Import the *.SPEOSLightBox file into Ansys Speos by using Light Box Import
- Perform System Level analysis
Note: If the supplier activates the black box option when exporting the light box, the OEM doesn’t have access to the geometries contained in the light box (only a bounding box is displayed in the 3D view), and the ray paths can’t be displayed within the system to avoid reverse engineering. The supplier's intellectual property is then protected while the OEM can still produce accurate results with the system.
The main tools needed for this example are:
- Ansys Speos 2024R2 or later version
- Ansys Zemax OpticStudio 2024R2 or later version
Export Optical Design from Ansys Zemax OpticStudio to Ansys Speos (Supplier)
The aim of this part is to generate the *.odx file which contains the geometries of the system with their position and orientation, the position and orientation of the imager, the materials and the coatings used in the optical system. This file will be imported in Ansys Speos in the next part.
Note: Here is the list of the optical elements from Ansys Zemax OpticStudio that can be exported to Speos - Understanding What Can Be Exported from Ansys Zemax OpticStudio
Once the optical design in Ansys Zemax OpticStudio is completed, *.odx file can be exported:
- Open the project “710_reoptimized_MTF_materials_QType_V5.zar” in Ansys Zemax OpticStudio
- Click on File>“Export Optical Design to Speos”
- Save the *.odx file with a custom path and name
- A pop-up saying the export was successful appears
Import Optical Design Exchange and generate black box Light Box Export in Ansys Speos (Supplier)
The aim of this part is to generate the *.SPEOSLightBox file which contains the optical elements coming from Ansys Zemax OpticStudio and the potential mechanical parts coming from Ansys Speos. With black box mode activated, the optical design is encrypted.
Optical Design Exchange:
- Open “Cellphone_lenses_Supplier.scdocx” project in Ansys Speos (it can be done from a blank new project if no mechanical parts are needed)
- Click on Light Simulation>Components>“Optical Design Exchange”
- Keep the default axis system
- Browse the *.odx file previously generated as Optical Component File
- Right-click on “Optical Design Exchange.1” in Speos tree to open the options and modify the meshing parameters as follow
- Compute the feature
- Geometries are created in both Speos and Structure trees
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- Sensors and their associated coordinate systems are created in Speos tree
- By double-clicking on a specific lens in Speos tree, you can see the parameters and optical properties linked to this lens
Light Box Export:
- Click on Light Simulation>Components>Light Box>“Export Speos Light Box”
- Keep the default axis system
- Set Black box parameter to True
- Notes: When importing a classic Light Box, the geometries are accessible in Speos tree and 3D view, which is not the case with a black box Light Box
- Activate the geometries selection tool
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- Select the following mechanical geometries in structure tree - this step is optional
- Select the Optical Design Exchange feature in Speos tree
- Compute the feature: *.SPEOSLightBox file is automatically generated in the output files folder of the project
Import black box Light Box in Ansys Speos (OEM)
The objective of this part is to import the *.SPEOSLightBox file in Ansys Speos.
- Open “Cellphone_lenses_OEM.scdocx” project in Ansys Speos
- Click on Light Simulation>Components>Light Box>“Import Speos Light Box”
- Keep the default axis system
- Browse for the .SPEOSLightBox file previously generated, located in the output files folder
- Note: The display mode is automatically set to bounding box to hide the geometries in 3D view
- Compute the feature
- Note: Geometries are not available in the Speos tree neither in the 3D view
The following screenshots show the difference between the imports of a Light Box with black box activated (geometries hidden) or not (geometries accessible)
Black box option set to True
Black box option set to False
Perform System Level analysis
In this part, we will see that it’s possible to perform system level analysis with a black box optical design.
- Edit the "Direct_BlackBox" simulation
- Activate the geometries selection tool and select "Light Box Import.1”
- Run the simulation with CPU or GPU
- Note: It is possible to activate light expert to analyze the optical paths outside the optical design but the rays inside the optical design will be hidden to avoid reverse engineering
- Open the XMP map and set the maximum illuminance value to 1e8 lux
Conclusion
It is now possible for suppliers to export an optical system from Ansys Zemax OpticStudio to Ansys Speos and transform it into an encrypted Speos Light Box. Then, the original equipment manufacturer can import the generated file and use it to perform system level analysis. The advantage of encrypting the Light Box is to protect the intellectual property by hiding the optical system and the ray paths inside it while preserving the optical simulation accuracy.