Waveguide data collection wizard

The waveguide data collection wizard allows you to automatically generate straight waveguide compact models using Ansys Lumerical CML Compiler™ based on the waveguide_simple photonic model using simulation files from Ansys Lumerical MODE™ .

Required licenses

Ansys Lumerical MODE™ GUI license
Ansys Lumerical CML Compiler license (For direct export of compiled INTERCONNECT models)

Preparing simulation files

The input to this wizard is a MODE project file (.lms), with the following requirements:

The simulation must have eigenmodes successfully solved and all target modes calculated and converged.
The group index for each mode of interest must be present. You can calculate the group index either through the frequency analysis tab, or through the advanced options inside the eigensolver analysis window for the FDE solver in MODE. When you calculate the group index through the advanced options setting, they are only calculated for one wavelength. As a result, the dispersion of the waveguide will be automatically set to zero. When both results are present, the wizard uses the frequency analysis results.

Starting the wizard

The waveguide data collection wizard package files are attached to this article. The attached files include the main wizard package as well as packages containing examples. Important files are as follows:

Configuration file: The JSON file in the wizard zip file /wizard/wg_simple_wizard/gui_config.json contains default configuration for this wizard. Ensure that the lumapi_path variable points to the lumapi.py file included with Lumerical products. You can find the default paths here.
Wizard scripts: The folder /wizard/ within the wizard zip file contains all necessary files to run this tool. You can start the wizard by running the python script named main.py under /wizard/wg_simple_wizard.
Examples: Several example input files are available in the example zip file.

Wizard interface

Model settings

The first page of this wizard contains input parameters for generation of the waveguide compact model.

Element Info: Enter the description and any notes for the model in this section. You can add multiple notes using the “Add Note” and “Delete Note” buttons.

Ports: Configure location, name and order of the ports on the symbol in this section. Use the default settings to create an element where the input and output ports are centered and are respectively on the left and right side of the waveguide element.

QA: Configure the wavelength range used for the waveguide quality assurance test.

Parameters: Enter the minimum, maximum, and the default length of the waveguide.

Mode Data: Select the modes of interest for the waveguide. Up to two modes are supported. Enter data as follows:

Mode #: Use the mode number in the “Mode list” of the eigensolver analysis window.
Mode ID: The numeric ID of each mode, only up to two modes are supported. The ID of each mode can be freely selected but must be consistent across the entire compact model library.
Name: Name of each mode.
Loss: Enter additional loss of each mode in this column. The wizard automatically extracts loss from the simulation file. Total loss information is displayed on the next page for confirmation.

Simulation File: Choose the MODE simulation file (.lms) the wizard will use.

After you finish entering model data, press “Next” to extract data from the MODE simulation file and proceed onto the setting up the output.

Output settings

The second page of the wizard contains a confirmation of model information, and settings for the output of the model.

Model Information: The scrollable top section of the window contains model information:

The “General Info”, “Parameters”, and “Simulation Settings” subsections contain information you entered on the previous page.
The “Mode Data” subsection contains information collected from the simulation file and information you entered. Specifically, the “Loss” column displays total loss, which is the sum of the loss you entered, and the loss extracted from the simulation file.

Element Name: Enter the desired element name in this field.

Icon: Choose an optional icon (.svg) for the element.

Library Mode: Pick the execution mode of the wizard, the selections are as follows:

Build INTERCONNECT Model: Generate compiled INTERCONNECT model in the /wizard/ folder of the script. You can import this model into INTERCONNECT by right clicking the “Custom” folder in the Element Library, and use “Redirect” to point to the location of the compiled models.
Add to Existing CML Database: Add extracted information into an existing CML database by selecting a master JSON file. When you select this option, an entry is added to the selected master JSON file, and model JSON files along with the icon (if specified) are added into the /source/ folder of the compact model library. You can then use CML Compiler to compile all models in that library.

Note: When you generate the compact model, numerous model parameters other than those extracted from the simulation file and those specified in the wizard are set to their default values. You can adjust the value of all model parameters prior to compilation by selecting “Add to Existing CML Database” and then modifying the model JSON file in the /source/ folder of the compact model library.

CML Compiler Path: Select the path to your cml-compiler executable file. After you select its path for the first time, the wizard uses the last entry for subsequent runs.

Once you have completed review of the model data and selected the output mode, press “Execute” to complete generation of the compact model.

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