Characterization of surface acoustic wave optomechanical oscillators

We describe and experimentally demonstrate an optomechanical oscillator where light drives a surface mechanical mode of a spherical resonator, using a combination of photoelastic scattering and optical electrostriction. These oscillators are shown to have discretely-selectable frequencies ranging from 50 MHz to 1.5 GHz on a single silica microsphere device. We also report on initial measurements of phase noise and continuous frequency tuning of these oscillators.