# Optomechanically Induced Birefringence and Faraday Effect

## TL;DR

This paper presents an optomechanical system that enables dynamic control of light polarization states, including birefringence and Faraday effects, through mechanical interactions in a Fabry-Perot resonator, allowing for advanced polarization manipulation.

## Contribution

It introduces a novel optomechanical platform that achieves arbitrary polarization control and non-reciprocal effects using mechanical motion and optical control fields.

## Key findings

- Demonstrated optomechanically induced birefringence and Faraday effect.
- Achieved full polarization control on the Poincaré sphere.
- Enabled tunable optical isolation and circulation.

## Abstract

We demonstrate an optomechanical platform where optical mode conversion mediated by mechanical motion enables arbitrary tailoring of polarization states of propagating light fields. Optomechanical interactions are realized in a Fabry-Per\'ot resonator, which naturally supports two polarization-degenerate states while an optical control field induces rotational symmetry breaking. Applying such principles, the entire Poincar\'e sphere is spanned by just optical control of the driving field, realizing reciprocal and non-reciprocal optomechanically-induced birefringence for linearly polarized and circularly polarized control driving. A straightforward extension of this setup also enables all-optical tunable isolation and circulation. Our findings open new avenues to exploit optomechanics for arbitrary manipulation of light polarization.