gds_fdtd

gds_fdtd is a minimal Python module to assist in setting up FDTD simulations for planar nanophotonic devices using FDTD solvers such as Tidy3D.

Features

• Automated FDTD Setup: Easily set up Lumerical and Tidy3D simulations for devices designed in GDS.
• Integration with SiEPIC: Generate FDTD simulations directly from components defined in SiEPIC EDA and it's associated PDKs (e.g., SiEPIC-EBeam-PDK).
• Integration with gdsfactory: Generate Tidy3D simulations directly from gdsfactory designs by identifying ports and simulation regions from an input technology stack.
• S-Parameter Extraction: Automatically generate and export S-parameters of your photonic devices in standard formats.
• Multimode/Dual Polarization Simulations: Set up simulations that support multimode or dual polarization configurations for device analysis.

Installation

You can install gds_fdtd using the following options:

Quick install (PyPI)

pip install gds-fdtd

Option: Basic Installation from source

To install the core functionality of gds_fdtd, clone the repository and install using pip:

git clone git@github.com:mustafacc/gds_fdtd.git
cd gds_fdtd
pip install -e .

Option: Development Installation

For contributing to the development or if you need testing utilities, install with the dev dependencies:

git clone git@github.com:mustafacc/gds_fdtd.git
cd gds_fdtd
pip install -e .[dev]

This will install additional tools like pytest and coverage for testing.

Editable + dev tools

pip install -e .[dev]

Optional extras

Requirements

• Python ≥ 3.10 (note: gdsfactory requires Python ≥ 3.11)
• Runtime deps: numpy, matplotlib, shapely, PyYAML, klayout

Running tests

If you've installed the dev dependencies, you can run the test suite with:

pytest --cov=gds_fdtd tests

## Development

### Version Management

This project uses `bump2version` to keep version numbers in sync across all files.

**Check current version:**
```bash
make check-version

Bump version:

# For bug fixes (0.4.0 -> 0.4.1)
make bump-patch

# For new features (0.4.0 -> 0.5.0)  
make bump-minor

# For breaking changes (0.4.0 -> 1.0.0)
make bump-major

Quick release:

# Does everything in one go
./scripts/release.sh [patch|minor|major]

This script will:

• Run tests and build docs
• Update version numbers everywhere
• Create a git tag
• Push everything to GitHub
• Trigger GitHub release and PyPI upload

Available Make Commands

make help          # Show all available commands
make install       # Install package in development mode
make test          # Run tests with coverage
make docs          # Build documentation
make docs-serve    # Build and serve docs locally on port 8000
make clean         # Clean build artifacts
make release       # Build package for release

Development Setup

For new contributors:

# Clone the repository
git clone https://github.com/SiEPIC/gds_fdtd.git
cd gds_fdtd

# Install development dependencies
pip install -e .[dev]

# Run tests
make test

# Build documentation
make docs

Making a Release

1. Make sure you're on the main branch with all changes committed
2. Run the release script: ./scripts/release.sh [patch|minor|major]
3. The script will automatically:
   • Run tests to make sure everything works
   • Build documentation
   • Bump version numbers in all files
   • Create and push a git tag
   • Trigger GitHub Actions to create a release and upload to PyPI

The GitHub Actions workflow will:

• Run tests again
• Build the package
• Create a GitHub release with changelog
• Upload to PyPI automatically