Chalcogenide-Ring Fiber Design for Brillouin Scattering with OAM Modes

Guided-wave Stimulated Brillouin Scattering (SBS) has paved the way for many microwave photonics (MWP) functionalities, such as tunable filters, frequency measurement systems and phase shifters [1]. Chalcogenide (especially As 2 S 3 ) has proven to be an excellent material platform providing large SBS gain in both fiber and on-chip devices [2]. We focus on inter-modal SBS, where the pump and Stokes can be spatially filtered out, with orbital angular momentum (OAM) modes (twisted states of light with helical phase fronts) that provide a large orthogonal basis to utilize for a variety of applications. Previously, SBS interaction between OAM modes in integrated devices has been numerically investigated only in complicated structures such as cross-shaped silicon waveguides [3]. In this work, we demonstrate the excitation of strong backward SBS using OAM modes in a simple chalcogenide-ring silica optical fiber design through numerical simulations [4].