Stimulated Brillouin scattering in chiral photonic crystal fiber

TL;DR

This paper presents the first experimental demonstration of stimulated Brillouin scattering in chiral photonic crystal fiber, showcasing its ability to maintain circular polarization and enabling stable circularly polarized Brillouin lasers for advanced photonic applications.

Contribution

It reports the first experimental study of SBS in chiral PCF, demonstrating optical activity and polarization stability, and realizing a circularly polarized continuous-wave Brillouin laser.

Findings

Chiral PCF maintains circular polarization against external perturbations.

Back-scattered Stokes signal has orthogonal circular polarization.

Chiral PCF enables stable circularly polarized Brillouin lasers.

Abstract

Stimulated Brillouin scattering (SBS) has many applications, for example, in sensing, microwave photonics and signal processing. Here we report the first experimental study of SBS in chiral photonic crystal fiber (PCF), which displays optical activity and robustly maintains circular polarization states against external perturbations. As a result, circularly polarized pump light is cleanly back-scattered into a Stokes signal with the orthogonal circular polarization state, as is required by angular momentum conservation. By comparison, untwisted PCF generates a Stokes signal with an unpredictable polarization state, owing to its high sensitivity to external perturbations. We use chiral PCF to realize a circularly polarized continuous-wave Brillouin laser. The results pave the way to a new generation of stable circularly polarized SBS systems with applications in quantum manipulation, optical tweezers, optical gyroscopes and fiber sensors.