Transformation Optics Simulation Method for Stimulated Brillouin ScatteringR. Zecca , P. T. Bowen , D. R. Smith , S. Larouche ,
 Center for Metamaterials and Integrated Plasmonics and Department of Electrical and Computer Engineering, Duke University, Durham, NC, USA
Stimulated Brillouin scattering (SBS) is a nonlinear phenomenon coupling optical and elastic waves. Traditionally regarded as an undesirable side-effect, it has garnered renewed interest as a platform for investigating slow light, nonreciprocity, and for designing high-performance chip-integratable optical elements. While the design of such devices relies on numerical simulations, frequency-domain full-wave SBS calculations are not readily achievable in COMSOL Multiphysics® software. In this work, we develop a novel approach to enable the simulation of SBS in COMSOL® software. The method uses transformation optics techniques to implement a time-harmonic coordinate transform that reconciles the different frames of reference used by the electromagnetic and structural mechanics solvers. We show how this strategy can be successfully applied to bulk and guided systems, comparing the results with predictions of established theory.