Generating novel waveguides for stimulated Brillouin scattering with generic algorithms

Over the last few years a rapid development has been going on in demonstrating stimulated Brillouin scattering (SBS) in chip-integrated optical waveguides. Most of the work has focused on finding good materials for achieving net gain however[1], rather than on exploring novel waveguide designs. To design a waveguide for high SBS gain is difficult because one needs to compromise between having a good optical waveguide, a good mechanical resonator, and a strong coupling between the two, all in the same physical structure. To approach this problem we used genetic algorithms (GA) and explored a wide range of possible waveguide shapes to achieve high gain in silicon and silicon oxide based integrated platforms. GAs have been shown to often provide counter intuitive but educational answers in domains ranging from the growth of plants and website design to Othello strategies[2,3]