For those writing parameter sweeps or integrating Lumerical with Python (via lumopt or scipy), this subforum is a goldmine. Search for topics on automating Monte Carlo simulations or exporting far-field data to MATLAB.
The Lumerical Forum is structured to cater to different physics solvers and applications. Understanding the layout will help you find answers faster:
It is not an exaggeration to say that hundreds of peer-reviewed papers have been directly enabled by the Lumerical Forum. For example, a 2022 Optics Express paper on topological photonic crystals explicitly thanked the forum in the acknowledgments for resolving a boundary condition issue. Similarly, a semiconductor foundry recently published a case study showing how a script shared on the forum reduced their Monte Carlo yield analysis from 12 hours to 45 minutes.
This is a post sharing a script to automate a parameter sweep.
Subject: [Script] Automating parameter sweeps for varying waveguide widths
Body: Hello community,
I wrote a simple script to automate the process of sweeping waveguide widths and exporting the effective index data to a text file. I thought this might be useful for others doing similar MODE calculations.
How to use:
Code:
# Define sweep parameters
width_start = 0.4e-6;
width_stop = 1.0e-6;
steps = 10;
# Open file for writing
filename = "neff_vs_width.txt";
f = fopen(filename, "w");
# Loop
for (i=0:steps-1)
current_width = width_start + i*(width_stop-width_start)/(steps-1);
# Update structure (assuming object named 'waveguide')
setnamed("waveguide", "x span", current_width);
# Run mode calculation
run;
# Get data
neff = getdata("mode1", "neff");
# Write to file
fprintf(f, "%e %e\n", current_width, neff);
fclose(f);
?"Sweep complete. Data saved to " + filename;
Hope this helps!
Are you looking for help with a specific Lumerical problem, or were you trying to format a post to submit?
The forum is part of the Ansys Customer Center and is designed to provide public community support, troubleshooting, and collaborative learning for researchers and engineers.
Official Platform: Access the Lumerical Forum directly on the Ansys Innovation Space.
Community Transition: In 2021, Lumerical's independent community support fully merged into the broader Ansys Learning Forum (ALF) to streamline resource access. Core Discussion Categories
Discussion is typically organized by product and physics solver to help users find relevant expert advice: FDTD: Designing and optimizing complex photonic components. MODE: Optical waveguide design and analysis. lumerical forum
CHARGE / HEAT / FEEM: Multiphysics simulations involving electrical, thermal, and mechanical interactions.
INTERCONNECT: Photonic integrated circuit (PIC) and system-level modeling.
Scripting & API: Automating tasks using Lumerical's scripting language or Python (PyLumerical). Recent Trending Topics (April 2026)
Recent activity on the Ansys Learning Forum highlights current user priorities and technical issues: Lumerical Forum - Ansys Customer Center The Ansys Learning Forum is a public forum. Ansys Innovation Space ANSYS LUMERICAL - Ansys Customer Center
This is a typical post from a user encountering a simulation error or convergence issue.
Subject: FDTD propagation error: "Electric field values are too large" in ring resonator simulation
Body: Hi everyone,
I am currently designing a silicon ring resonator using MODE and FDTD. I am encountering a divergence error during the simulation run.
System Details:
Description: I have set up a 2D simulation of a ring resonator. I defined the silicon core with a mesh override region to resolve the 1550nm wavelength properly. However, after roughly 20% of the simulation time, the job manager reports: "WARNING: Electric field values are too large... simulation diverging."
I have checked my boundary conditions (PML) and ensured that the structure does not touch the simulation region edges.
Steps I have tried:
Screenshots: (Attached image showing the mesh region and the log output)
Does anyone have suggestions on how to stabilize this simulation? Any advice would be appreciated. For those writing parameter sweeps or integrating Lumerical
Thanks, User123