Stimulated Brillouin Scattering (SBS) enables strong light–sound interactions for applications in narrow-linewidth lasers, signal processing, and quantum transduction. While silicon platforms offer limited SBS performance, anisotropic materials like Lithium Niobate (LNO) and Lithium Tantalate (LT) unlock new opportunities through enhanced photoelastic coupling and crystallographic control. In this talk I’ll review our recent progress in these materials: (1) strong cross-polarized backward SBS in LNOI waveguides, where TE and TM modes interact via shear surface acoustic waves. The observed gain exceeds 80 m⁻¹W⁻¹ and arises from a nontrivial photoelastic tensor component, enabling polarization-sensitive Brillouin devices; (2) our progress investigating SBS in LTOI. These results mark a shift toward vectorial Brillouin photonics, where polarization and crystal orientation serve as design
parameters. LNOI and LTOI together offer a flexible materials platform for scalable, tunable, and multifunctional SBS-enabled photonic systems.