Overview

cbeam is a propagator for slowly varying and weakly guiding waveguides, written in Python and Julia.

Documentation

How to install

Current version: v0.0.4

Dependencies

Python: numpy,scipy,numexpr,juliacall,wavesolve,pygmsh,meshio,matplotlib

Julia: pythoncall

General: Gmsh

Details

This package uses coupled-mode theory to simulate propagation through waveguides, under the weak guidance, paraxial, and slowly varying envelope approximations. Wavefronts are decomposed in the basis of instantaneous eigenmodes, so that cbeam remains applicable even when a static eigenbasis does not exist (the case for tapered waveguides such the photonic lantern), as well as cases where the eigenbasis becomes degenerate. It's also relatively fast; a 6-port lantern can be characterized in around a minute, and simple $2\times 2$ directional couplers take ~10 s (on my desktop, which has an AMD 5900x cpu). See the online documentation for installation instructions, examples, and further reference. For a brief writeup of the theory behind cbeam, check out this arXiv paper.

Acknowledgments

NSF grants 2109231, 2109232, 2308360, 2308361