GitHub - UMassIonTrappers/PyOpticL: PyOpticL: a code-to-CAD optical layout tool for modular optics systems engineering

PyOpticL (Python Optics Layout) is a Python library for code-to-CAD design of optical systems using modular baseplates. It places optics along simulated beam paths, including branched beam paths, so routing is automatic and dynamic as optics are added or modified. Baseplates are designed to be easily machined or 3D printed and mounted on an optical table. Baseplates are easy to set up as aligning optics on the baseplate is like 'paint by numbers', with each optic having a pre-aligned mount. Baseplates are reusable building blocks that can be combined into modular subsystems. Subsystems are also reusable at various wavelengths such that they can be easily combined into many different experimental apparatuses.

If you use PyOpticL in your research, please cite our paper published in Quantum. The paper introduces PyOpticL and demonstrates its use in a trapped-ion quantum computing experiment, including laser cooling, state detection, and high-fidelity qubit operations.

What can I design and build with PyOpticL?

• Laser Pulse Control Systems
• Extended-Cavity Diode Lasers (ECDLs)
• Saturation Absorption Spectroscopy
• Qubit Laser Systems
• Neutral Atom Quantum Computer
• Trapped Ion Quantum Computer

Code Structure

baseplate = Component(...)
beam = baseplate.add(BeamPath(...))

beam.add(mirror())
beam.add(waveplate())
beam.add(beamsplitter_cube())

Used by researchers at:

MIT • Stanford • UC Berkeley • UMass Amherst • UW Madison • UConn • NUS • Quera • Harvard • CalvinQ

Readme contents:

• Installation
• Quick start
• Publication
• Wiki
• Baseplate Examples
• Subsystem Examples
• Apparatus Examples
• PyOpticL Community

Publication – High-Fidelity Trapped-Ion Qubit Operations with PyOpticL

We use PyOpticL in our trapped ion laboratory at UMass Amherst to design modular optical systems for trapped-ion quantum computing. In this paper we demonstrate laser cooling, state detection, and >99% fidelity single-qubit gates in our trapped-ion system using PyOpticL baseplates and lasers.

Read the paper

• Quantum (2026):
  Qubit operations using a modular optical system engineered with PyOpticL: a code-to-CAD optical layout tool

• arXiv preprint:
  arXiv:2501.14957

Citation

Please cite our paper if you use PyOpticL. Thank you!

Myers, J., Caron, C., Helaly, N., Wei, Z., Oh, J., Gotobed, Z., Yabe, K., & Niffenegger, R. J.
Qubit operations using a modular optical system engineered with PyOpticL: a code-to-CAD optical layout tool.
Quantum 10, 2135 (2026).

UMass Amherst Trapped Ion system built with PyOpticL:

Modular abstraction: Optics → Baseplates → Subsystems → Apparatus:

Getting Setup

1. Install FreeCAD, Python, and Git

2. Add PyOpticL as a custom addon repository in FreeCAD
   Under Edit>Preferences>Addon Manager>Custom Repositories, click the plus icon and enter the following information:
   Repository URL: https://github.com/UMassIonTrappers/PyOpticL.git
   Branch: main
   Press OK to save settings

3. Install the PyOpticL library In the Addon Manager (Tools>Addon Manager), search for "PyOpticL" and click install.
   Note: if you get an error related to git, try disabling it - Edit>Preferences>Addon Manager>Disable git

4. Check everything is setup correctly
   You should now be able to re-launch FreeCAD and see the "PyOpticL" workbench in the workbench dropdown

5. Check out the wiki for guides on how to get started and examples

PyOpticL v2.0 🚀 released! It is a complete rewrite of the PyOpticL library!

• Migrate from 1.0 to 2.0
• v2.0-Highlights
  • Including Improved Optics Simulation (Gaussian beam simulation)

Wiki

• Installation Guide
• Quick Start Guide
• Contributing to PyOpticL

Modular baseplate examples:

• Laser - Extended Cavity Diode Laser (with optical isolator)
• Doublepass AOM Baseplate
• Singlepass AOM Baseplate
• Saturation Absorption Spectroscopy Baseplate
• Periscope
• CoverBox

Modular Subsystems based on baseplates:

• Laser Cooling and Detection
• Raman Zeeman qubit
• Photoionization
• State Preparation and Measurement

Apparatus based on modular subsystems:

• Trapped Ions - Strontium
• Trapped Ions - Calcium
• Project Redstone

Baseplate Examples and Designs

• Designs
• 3D Models and Technical Drawings

Pre-made Layouts

Macro files for pre-made layouts can be found in the PyOpticL directory. This can be found in:
<FreeCAD User Data Directory>/Mod/PyOpticL/Design
On windows this is:
%APPDATA%\FreeCAD\Mod\PyOpticL\Design

PyOpticL v1/v2 Migration

The main branch of this project has been updated to PyOpticL v2.0! This is a breaking change for existing designs. Unless you manually update PyOpticL within FreeCAD, existing installs should be unaffected.

If you need to install v1:

• Use Branch: v1-legacy when following the install instructions

To update to v2.0:

• Backup all locally changed files (optomech.py, stls, etc.)
• Uninstall PyOpticL from addon manager (This will delete all PyOpticL source files, backup your changes)
• Restart FreeCAD
• Re-install PyOpticL

PyOpticL Community:

Join the discussion on our Discord server: https://discord.gg/vV4NP6rXmp

Experimental Labs using PyOpticL:

• MIT QUANTA LAB - Prof. Isaac Chuang (Ba⁺ & Sr⁺)
• MIT Quantum Photonics & AI Group - Prof. Dirk Englund (Rb)
• UC Berkeley - Prof. Aziza Suleymanzade (Rb)
• UW Madison - Prof. Josiah Sinclair (Rb)
• UCONN - Prof. Simone Colombo (Rb, Sr)
• Montana State University - Prof. Matt Jaffe (Rb)
• National University of Singapore - Prof. Dzmitry Matsukevich (Yb⁺)
• Stanford - Prof. Jonathan Simon (Rb)
• Durham University Quantum Light and Matter - Tobias Franzen (Yb), Dani Pizzey (Rb)
• Quera (Rb)
• Harvard University (Rb)
• Calvin Q (Rb)

We thank Ike and the MIT QUANTA LAB for sharing their C4PO ('CAD for Precision Optics') based on OpenSCAD which inspired this library.