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?
Exploring the Frontiers of Photonics with Lumerical
In the rapidly evolving field of photonics, where the manipulation of light is key to unlocking new technologies, simulation plays a crucial role in design and development. Lumerical, a leading company in this space, provides engineers and researchers with powerful tools to model and analyze complex photonic structures and systems. The Lumerical forum, a vibrant community of users and experts, stands as a testament to the company's commitment to collaboration and innovation.
The Power of Simulation in Photonics
Photonics, with its applications ranging from telecommunications and data centers to bio-medical devices and quantum computing, requires precise and efficient design and testing methodologies. Physical prototyping can be expensive, time-consuming, and sometimes impractical for exploring new ideas. This is where Lumerical's software solutions shine, offering a virtual laboratory for testing and optimizing photonic devices and systems.
Lumerical's tools, such as FDTD Solutions, MODE Solutions, and Interconnect, are built on rigorous mathematical models that simulate the behavior of light in various photonic structures. These simulations can predict performance metrics, identify potential issues, and guide design optimization, significantly reducing the need for physical prototypes and accelerating the path to commercialization.
The Lumerical Forum: A Hub for Innovation
The Lumerical forum is more than just a technical support site; it's a dynamic community where users can share knowledge, showcase their work, and get feedback from peers and Lumerical experts. This platform facilitates the exchange of ideas across different sectors of the photonics industry, from academic researchers to engineers in R&D.
Users of the forum can find and discuss various topics, including:
Engaging with the Community
Engagement on the Lumerical forum opens up numerous opportunities for individuals and organizations working in photonics. By participating in discussions, users can:
Conclusion
The Lumerical forum embodies the spirit of collaboration and innovation that is essential for advancing photonics and nanotechnology. By providing a platform for users to share, learn, and discuss, Lumerical not only supports its customers' immediate technical needs but also fosters a community that drives the field forward. As photonics continues to play a more significant role in our daily lives and technology, platforms like the Lumerical forum will be at the forefront, facilitating the exchange of ideas and accelerating innovation.
The Lumerical Forum has officially moved from its original Knowledge Exchange (KX) platform to the Ansys Learning Forum (ALF) as part of the integration into the Ansys ecosystem. Key Features of the New Forum Platform
The current forum, hosted on the Ansys Customer Center, offers several interactive and organizational features:
Integrated Search & Filters: Users can quickly sort posts by Newest, Most Liked, Most Comments, Most Views, or Recent Activity.
Photonics Specificity: Within the Ansys Learning Forum, Lumerical support is categorized under the Photonics section, where users can ask questions related to FDTD, MODE, and CHARGE.
Personalization Tools: Logged-in users can use Bookmarks to track important threads and Saved Drafts to work on complex technical questions before posting.
Direct Expert Support: Lumerical Application Engineers actively monitor the new site to provide official technical guidance.
Knowledge Integration: The forum is linked to the Ansys Knowledge Base, which includes "Watch & Learn" video tutorials and application galleries. Important Posting Guidelines
New Account Required: Users must create a new account on the Ansys Learning Forum; previous Lumerical KX credentials do not transfer.
No File Attachments: A key security policy is that Ansys employees cannot download attachments. Users are encouraged to use screenshots to show project settings or script errors for feedback.
Public Access: Support registration is not required to browse the ALF, making it more accessible for prospective users and students.
The Lumerical Forum: A Cornerstone for Photonic Design and Simulation Support
In the rapidly evolving field of photonics, accurate simulation and modeling are critical for success. Ansys Lumerical has established itself as the industry standard for photonic simulation, providing tools that span from component-level device design to system-level integration. However, the true power of this software ecosystem is amplified by the Lumerical Forum, a vibrant, expert-driven community hub designed to support engineers, researchers, and students. lumerical forum
This article explores the Lumerical Forum, highlighting its role as a crucial resource for troubleshooting, learning, and collaboration in the simulation community. What is the Lumerical Forum?
The Lumerical Forum is an official, user-focused discussion platform hosted by Ansys. It serves as a bridge between users and the developers of FDTD, MODE, CHARGE, HEAT, and INTERCONNECT.
Unlike generic support channels, the forum is a public repository of knowledge where discussions are indexed, allowing users to find solutions to complex problems encountered by others over the past decade. Key Purposes of the Forum:
Technical Support: Direct interaction with Ansys experts to solve simulation challenges.
Knowledge Sharing: A platform for sharing tips, tricks, and optimized scripts.
Community Collaboration: A space for researchers to discuss simulation methodology and validate results. Why the Lumerical Forum is Essential
Whether you are a novice attempting your first FDTD simulation or an experienced researcher optimizing a complex photonic integrated circuit (PIC), the forum offers unparalleled value. 1. Expert Troubleshooting
Photonic simulations can be sensitive to boundary conditions, meshing, and material parameters. When simulations fail to converge or provide unexpected results, the forum enables users to post their project files (.fsp, .lms, .icp) for expert review.
Example: Solutions for optimizing mesh settings to balance accuracy and simulation time. 2. Scripting and Automation Assistance
Lumerical uses a powerful scripting language to automate design workflows and analyze data. The forum is the best place to find ready-to-use scripts for complex tasks such as complex scattering analysis, material fitting, or custom visualization [2]. 3. Industry-Academia Collaboration
The forum brings together users from leading universities and industry giants. This creates a unique environment where the latest, most advanced modeling techniques are shared alongside fundamental simulation principles [3]. 4. Direct Feedback to Developers
The community directly influences the roadmap of Lumerical tools. Users frequently post suggestions for new features, improving the software's functionality to match the needs of the industry. How to Effectively Use the Lumerical Forum
To get the most out of the forum, it is essential to follow best practices for posting and searching.
Search First: Before posting, use the search bar to see if your problem has already been solved. The forum contains years of history.
Be Specific: When asking a question, provide details on the solver used, the physical phenomenon being modeled, and the specific error message.
Share Files: The fastest way to get help is to upload your simulation file.
Use Proper Tags: Tag your posts with the relevant product (e.g., FDTD, MODE) and topic (e.g., Scripting, Materials) to ensure it reaches the right experts. Top Topics Discussed on the Forum
The forum covers the entire gamut of Lumerical’s product suite, with popular topics including: FDTD & Boundary Conditions
Discussions often revolve around setting up Perfectly Matched Layers (PML) and finding the correct simulation volume to prevent artificial reflections. Material Modeling
Users frequently ask how to accurately import or define customized, dispersive materials, particularly when dealing with metamaterials or non-linear optical properties. PIC Design (INTERCONNECT)
As PIC design becomes more complex, the forum is a hub for connecting device-level simulations (FDTD/MODE) to system-level circuits in INTERCONNECT, focusing on scattering parameters and circuit optimization. Active/Passive Device Simulation (CHARGE/HEAT)
Integrating CHARGE for optoelectronic devices and HEAT for thermal management in waveguide structures. Conclusion
The Lumerical Forum is not just a support portal; it is an invaluable community asset. By providing a platform for direct engagement with experts and peers, it accelerates the learning curve for new users and provides advanced troubleshooting for experts.
For anyone working with Ansys Lumerical tools, participating in the forum is an essential part of mastering photonic design and ensuring simulation success.
Disclaimer: This article is for informational purposes. For official support, always refer directly to the Ansys Lumerical Forum. g., FDTD simulation of waveguides)?
Create a tutorial on how to post a question for the best response?
Explain the difference between the forums and the knowledge base?
Ansys Lumerical Forum (now part of the Ansys Innovation Space
) is the primary community hub for photonics engineers and researchers using Lumerical’s simulation suite. Below is a review of the forum based on its features and community feedback.
The forum serves as a critical support layer for users of FDTD, MODE, CHARGE, and other solvers. It transitioned from the legacy "Knowledge Exchange" (KX) to a unified Ansys platform, which initially met some user resistance due to broken legacy links but has since matured into a well-structured resource. Key Features Expert Moderation : Posts are frequently monitored and answered by Ansys employees and application engineers Searchable Knowledge Base : Users can filter posts
by "New," "Unanswered," or "Answered" questions, making it easier to find verified solutions. Application Examples : The forum is closely linked with the Ansys Optics Application Gallery This is a post sharing a script to
, which provides validated templates for everything from metalenses to OLED modeling. Scripting Support : A major highlight is the community's help with Lumerical Scripting Language (LSF) and Python API automation. Your Products. Your Support. - Ansys Optics
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.
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
Ansys Lumerical Forum (often referred to as the Ansys Customer Center - Photonics Forum
) is a technical hub where engineers and researchers troubleshoot complex electromagnetic simulations. Discussions typically center on fine-tuning solvers like
to handle everything from nanoscale material fits to large-scale photonic integrated circuits (PICs). Ansys Innovation Space Core Technical Pillars of the Forum
The forum's most "deep" or recurring advanced topics include: Solver Convergence & Stability
: Users frequently grapple with "diverging" simulations. Experts recommend checking PML (Perfectly Matched Layer) boundary conditions and reducing the
only after identifying root causes, such as material fit issues or mesh refinement errors. Material Modeling : A major point of deep dives is the Material Explorer . Users share scripts for sampled data materials
and discuss how to achieve high-quality permittivity fits for broadband simulations. Inverse Design & Optimization : The forum is a primary resource for the LumOpt framework
. Engineers use it to generate non-intuitive shapes, such as waveguide crossings with near-perfect transmission, by combining gradient-based optimization with Maxwell's equations. Mesh Order Management
: A subtle but critical topic is using "mesh order" to simulate overlapping objects (e.g., core-shell nanoparticles) without complex boolean geometry. Ansys Innovation Space Expert Advice for Common Bottlenecks Photonics - Ansys Customer Center
| Symptom | Likely fix |
|---------|-------------|
| FDTD diverging | Increase mesh, reduce time step, check material fitler |
| CHARGE not converging | Increase iteration limit, refine mesh at junction, check BCs |
| Monitor data looks NaN | Run with smooth mesh off, check geometry overlap |
| INTERCONNECT error | Check element names for spaces, rebuild netlists |
| Script error “unexpected symbol” | Verify Lua syntax – use ? command in script prompt |
Use this guide to become effective on the Lumerical forum. When in doubt, search first, then post a minimal working example. The community and Ansys engineers are active, but good questions get answered within 24–48 hours.
Title: Optimizing FDTD Simulation of a Photonic Crystal Structure
Description:
Hi everyone,
I'm working on simulating a photonic crystal structure using Lumerical's FDTD solver. I've been trying to optimize the simulation to achieve accurate results within a reasonable computation time. I'd love to hear from others who have experience with similar simulations.
My structure consists of a 2D array of air holes in a silicon background, with a lattice constant of 500 nm. I'm using a Gaussian source with a wavelength range of 1500-1600 nm. I've meshed the structure with a maximum mesh size of 20 nm.
To optimize the simulation, I've tried the following:
However, I'm still experiencing some issues with accuracy and computation time. Has anyone else encountered similar challenges? What strategies have you used to optimize your FDTD simulations?
Specifically, I'd like to know:
Any advice or insights would be greatly appreciated. I've attached my simulation file (.lms) for reference.
Attachments: photonic_crystal.lms
Tags: FDTD, photonic crystal, optimization Code: # Define sweep parameters width_start = 0
This post is well-written because it:
The official hub for Lumerical support is the Ansys Learning Forum (ALF), which replaced the old Lumerical Knowledge Exchange (KX). This forum is the primary place to troubleshoot simulations, discuss photonics design, and interact with Ansys application engineers. Getting Started on the Forum
Account Setup: You must create a dedicated Ansys Learning Forum account to post questions or replies; old KX credentials are not automatically linked.
Primary Category: Most Lumerical discussions are found under the Photonics Category, which includes sub-tags for specific tools like FDTD, MODE, and CHARGE.
Browsing Content: Use the Lumerical Forum search to filter by "Answered Questions" or sort by "Recent Activity" to find existing solutions before posting. Effective Posting Guidelines
No File Attachments: A critical rule of the ALF is that Ansys employees are not permitted to download user attachments.
Use Screenshots: Instead of project files, provide clear screenshots of your simulation settings, geometry, and error messages to get feedback.
Be Specific: When posting a new thread, include the specific Lumerical product version you are using and clearly describe the expected vs. actual results. Key Resources and Tags
Application Gallery: For pre-built examples, check the Lumerical Application Gallery, which is often linked within forum discussions.
Innovation Courses: Many forum answers point to free Ansys Innovation Courses for deeper technical background on simulation theories.
Common Tags: Discussions are frequently organized by tags such as Creating Monitors, Material Database, and Interoperability.
The "Lumerical Forum," officially part of the Ansys Learning Forum (ALF)
, is the primary community support hub for users of Ansys Lumerical photonics simulation software. It serves as a technical exchange for engineers and researchers working on nanophotonic devices, circuits, and systems. Ansys Innovation Space Core Purpose and Community Role Technical Support:
Users post queries regarding simulation errors, script usage, and product licensing. Knowledge Exchange:
It replaced the former "Lumerical Knowledge Exchange (KX)" in April 2021 to integrate Lumerical support into the broader Ansys ecosystem. Expert Interaction:
Support is provided by both Ansys Application Engineers and high-contributing community members. Ansys Innovation Space Key Discussion Topics
The forum is organized into categories and tags to help users navigate complex multiphysics workflows:
Deep dives into FDTD (Finite-Difference Time-Domain), MODE, RCWA (Rigorous Coupled-Wave Analysis), and CHARGE solvers. Design Optimization: Discussions on inverse-design and topology optimization. Automation:
Guidance on using the Lumerical Python API and custom scripting for automated design processes. Interoperability:
Workflows connecting Lumerical with other Ansys tools like Zemax OpticStudio, Speos, and HFSS. Ansys Innovation Space Forum Features Searchable Knowledge Base:
A vast archive of "Answered Questions" that acts as a crowdsourced manual for troubleshooting. Ansys Innovation Space: Integrated with Ansys Innovation Courses to provide structured learning alongside community advice. Public Access:
While some advanced support requires a subscription, the forum remains a public resource for the global photonics community. Ansys Innovation Space Primary Solvers Covered Lumerical Forum - Ansys Customer Center The Ansys Learning Forum is a public forum. Ansys Innovation Space Photonics - Ansys Customer Center
While the Lumerical Forum is the best official source, you should also leverage:
| Resource | Link / Access |
|----------|----------------|
| Ansys Knowledge Base | https://support.ansys.com – search “Lumerical” for KB articles |
| Official Lumerical Documentation | Inside Lumerical: Help → Lumerical Help or online via Ansys Help |
| GitHub Examples | https://github.com/ansys/lumerical-examples |
| Training (free/paid) | Ansys Learning Hub → Lumerical courses |
| Python API (lumapi) | Docs in PYTHON_API/ of Lumerical install |
If you are new to photonics simulation, the learning curve can feel vertical. The user manual explains what each button does, but it rarely explains why your simulation diverges at specific time steps. Here is why the Lumerical Forum is a game-changer:
The Lumerical Forum is the official community hub hosted by Ansys (which acquired Lumerical Inc. in 2020). It serves as a centralized platform where users of all levels—from PhD students to silicon photonics veterans—ask technical questions, share knowledge, and discuss best practices.
Unlike generic programming forums, the Lumerical Forum is deeply specialized. Every thread revolves around the nuances of the finite-difference time-domain (FDTD) method, eigenmode expansion (EME), or the scripting language (Lumerical Scripting Language, or LSF). Crucially, the forum is actively monitored by Ansys’s support engineers and application experts, ensuring that high-level queries receive authoritative responses.
In the high-stakes world of nanophotonics, semiconductor design, and metamaterials, simulation accuracy is everything. Engineers and researchers using Ansys Lumerical—whether for FDTD, MODE, or the INTERCONNECT suite—often find themselves at a crossroads. The software is powerful, but the physics is complex.
This is where the Lumerical Forum becomes an indispensable asset. Far more than a standard Q&A board, the official Lumerical community is a dynamic ecosystem of peer-to-peer support, expert verification, and script-sharing. Whether you are debugging a divergent simulation or optimizing a grating coupler, mastery of the Lumerical Forum can cut your development time in half.
Because the community is technical, the quality of the answer correlates directly with the quality of the question. To get a solution within hours (not days), follow these protocols: