Real-time electrical tuning of an optical spring on a monolithically integrated ultrahigh Q lithium nibote microresonator

Abstract

Cavity optomechanics, the study of the interplay between light and mechanical properties of matter, has triggered a wide range of research from cavity quantum electrodynamics, label-free single molecule detection to the creation of phonon lasers. Using femtosecond laser direct writing followed by chemomechanical polishing, here we report an ultrahigh quality ($Q\sim {10}^7$) factor lithium niobate whispering gallery microresonator monolithically integrated with inplane microelectrodes. Coherent regenerative optomechanical oscillation with an effective mechanical quality factor as high as $2.86\times {10}^8$ is observed in air. We demonstrate real-time electrical tuning of the optomechanical frequency with an electromechanical tuning efficiency around $-134\mathrm{kHz}/100\mathrm{V}$.