Project Overview

This repository contains a complete optimization workflow that couples MATLAB with Lumerical FDTD to design and fine-tune nanophotonic structures. It uses a multi-objective genetic algorithm (gamultiobj) to optimize geometric parameters—such as silicon layer thickness, ring resonator dimensions, and periodicity—to minimize propagation losses in dual-polarized optical simulations.

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What This Project Does

The code interfaces directly with Lumerical using its MATLAB API to:

• Modify simulation parameters dynamically (e.g. radii, gaps, heights)
• Run electromagnetic simulations using Lumerical FDTD
• Extract electric field data and compute a figure of merit based on FWHM
• Store optimized results into a text log for further analysis

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Ideal For

This setup is ideal for:

• Silicon photonics research
• Metasurface or optical waveguide design
• Simulation-driven geometry optimization
• Projects requiring polarization-aware, multi-parameter tuning

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Project Structure

• optimizer_lum_mix.m – Main optimization function using dual-polarization runs.
• optimizer_lum.m – Sub-function that modifies simulation parameters, runs Lumerical, and extracts figures of merit (FWHM-based loss).
• results.txt – Appended file storing results from successful optimization runs.
• test1_b.fsp – Lumerical FDTD project file containing the base simulation setup.
• main_script.m – Initializes the MATLAB-Lumerical API, retrieves initial parameters, and runs the optimizer.

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Requirements

• MATLAB (Tested with R2021+)
• Lumerical FDTD Solutions (v202 or compatible)
• MATLAB API for Lumerical installed and path added:

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How to Run

1. Clone this repository:

git clone https://github.com/yourusername/lumerical-optimizer.git
cd lumerical-optimizer

2. Open MATLAB, set your working directory to the repo folder.

3. Make sure your Lumerical FDTD file path is correctly set in main_script.m:

4. Run the main script

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Optimization Details

Variables Optimized:

• Silicon height, breadth

• Inner/outer radii of concentric rings

• Gap between features

• Rect width, periodicity, etc.

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⚠️ Notes

• You must modify the code to match your own .fsp file structure — this includes renaming monitors, structures, or sources (e.g., "structure_group", "monitor_2", "source") as used in your own simulation file.

• Lumerical must be installed and licensed on the same machine as MATLAB.

• Consider parallelizing for speed by setting 'UseParallel',true in optimoptions.

License

This project is licensed under the GNU General Public License v3.0 – see the LICENSE file for details. You are free to use, modify, and distribute this code, but derivative works must remain open-source and patent use is restricted.