Internal frequency mixing in a single optomechanical resonator

Abstract

In this letter, we observe that both the fundamental radial breathing mode and the flapping mode couple to a high Q optical mode and generate frequency mixing through the nonlinear optical transfer function in a single nitride optomechanical resonator. The harmonic generation of the flapping mode produces a comb-like frequency mixing spectrum. Instead of using the external pump modulation, we show that the regenerative oscillation of an internal mechanical mode can be used as a modulation source for optomechanical RF mixing.