An Introduction to Floquet Photonics

Floquet photonics studies optical and electromagnetic systems whose properties vary periodically in time. Just as a spatial crystal couples waves through a repeating structure, a time-periodic medium can couple different frequencies.

This viewpoint provides a compact language for phenomena such as frequency conversion, nonreciprocal wave transport, and synthetic dimensions. The central computational challenge is to represent the coupled harmonics accurately while keeping the model efficient enough to reveal the underlying physics.

This short note is a starting point. Future revisions will add equations, numerical examples, and links to related research.