Ansys Lumerical FDTD™, Ansys Lumerical MODE™, and Ansys Lumerical Multiphysics™ software offer the ability to directly import and simulate device geometries from cells (fixed and parametrized) from Synopsys OptoCompiler™ for photonic component design. This article describes the in-product interfaces and tools used for this process and provides resources on manual steps that you need to do.
For detailed application examples that utilizes this workflow, see the Workflow examples section for photonic component design in the Knowledge Base article on Lumerical-OptoCompiler Integration.
Requirements
Prior to using this workflow, set up your OptoCompiler electronic-photonic design automation (EPDA) environment using the instructions in the Knowledge Base article on setting up the Lumerical-OptoCompiler environment for photonic component design.
Importing geometry from OptoCompiler
Accessing through the GUI
You can directly import elements from the OptoCompiler library using the Layout Geometry Wizard. Follow the steps below to import your geometry.
- Open the Layout Geometry Wizard for FDTD, MODE or Multiphysics. This button is under the Build group of the Design tab for FDTD and Multiphysics and is under the Build button in the top toolbar for MODE.
Ansys Lumerical FDTD™ and Ansys Lumerical Multiphysics™
Ansys Lumerical MODE™ - Select the Source type as OptoCompiler and select your lib.defs file. Then, click Next.
- Specify your component by selecting it in the Geometry source options, and assign a
.layermapas the layer map file and a.lbrfile as the process file in the Layer source options. - Review parameters for the target geometry, and confirm that layer mapping information shows the expected technology information for the layer map and process you selected. Then, click Finish to complete the geometry import.
- Enable the “Initialize FDTD region and ports (BETA)” flag to automatically add ports and an FDTD simulation region upon the completion of import. This is only applicable in FDTD.
- Click Finish to complete the geometry import.
Geometry import is now complete, and you can proceed on setting up and running the simulation.
Accessing through script
You can also use the wizard with a script using the built-in script command drivewizard, the list of inputs for the wizard can be obtained using the getwizardinputs.
# Get the layout geometry wizard inputs as a structure
?out=getwizardinputs("layout geometry wizard");
# Import 1x2 MMI with layout geometry wizard
wizard_settings = struct;
layout_tool_page = struct;
layout_tool_page.source = "optocompiler";
layout_tool_page.libconfig = <libs.def file location>;
geometry_source_page = struct;
geometry_source_page.library = "CustomLib";
geometry_source_page.cell = "MMI_1x2";
geometry_source_page.view = "layout";
geometry_source_page.layerMap = <.layermap file location>;
geometry_source_page.processFile = <.lbr file location>;
wizard_settings.layout_tool = layout_tool_page;
wizard_settings.geometry_source = geometry_source_page;
drivewizard("layout geometry wizard", wizard_settings);
Setup Lumerical simulation for imported components
Adjusting geometry parameters
During import, Lumerical automatically creates user properties for the object identical to those in the OptoCompiler library. You can freely edit the values for these objects in the Edit analysis group window, and the software will update in real time the geometry, the ports if they were initialized, and the FDTD region if it was initialized.
Adjusting waveguide extensions
The following only applies if you enabled automatic initialization of ports and FDTD region during the import.
The add_extended_waveguides option in the Edit analysis group window, enabled by default, automatically adds waveguides beyond the imported structure, such that they extend beyond the PML region of the FDTD simulation, which is very often required for accurate simulations.
You can manually adjust the waveguide dimensions and materials via extended_waveguide_length, extended_waveguide_height, and extended_waveguide_material.
Note: If the sidewall angle is not 90 degrees in the imported structure, there will be a mismatch between the extended waveguide and the imported layout. In this case, a warning is shown in the script prompt in FDTD.
Setting up Lumerical simulation
The direct bridge currently does not offer the ability to automatically set up Lumerical simulation regions and ports to conduct component simulations. You must manually set up ports and simulation regions either via script or the GUI.
For more information setting up simulations, see the FDTD Product Reference Manual and MODE Product Reference Manual. You can also refer to the workflow example that demonstrates setting up the simulation with an imported 1x2 Multi-Mode Interferometer.
Exporting models to OptoCompiler
To export completed component designs back to OptoCompiler, you can generate a compact model with Ansys Lumerical CML Compiler™, and use it with OptoCompiler. CML Compiler offers generation of INTERCONNECT CML models, which you can simulate in OptoCompiler by running INTERCONNECT as an engine, as well as through PrimeSim photonic Verilog-A models.
For further information, see Using INTERCONNECT as an engine in OptoCompiler, Using an INTERCONNECT Compact Model Library (CML) in OptoCompiler, and Generating photonic Verilog-A models for OptoCompiler.
See Also