Electrostatic actuation of silicon optomechanical resonators

TL;DR

This paper demonstrates the integration of electrostatic capacitive actuation with optical sensing in silicon optomechanical resonators, enabling electrical control and optical detection of mechanical vibrations at high frequencies.

Contribution

It introduces a monolithic integration approach combining electrostatic actuation with optical sensing in silicon optomechanical disks, advancing on prior separate methods.

Findings

Electrical excitation at 235 MHz modulates optical intensity.

Mechanical motion is directly observed via optical signals.

Integration enables electrical control of optical resonances.

Abstract

Optomechanical systems offer one of the most sensitive methods for detecting mechanical motion using shifts in the optical resonance frequency of the optomechanical resonator . Presently, these systems are used for measuring mechanical thermal noise displacement or mechanical motion actuated by optical forces. Electrostatic capacitive actuation and detection have been shown previously for silicon micro electro mechanical resonators for application in filters and oscillators. Here, we demonstrate monolithic integration of electrostatic capacitive actuation with optical sensing using silicon optomechanical disk resonators and waveguides. The electrically excited mechanical motion is observed as an optical intensity modulation when the input electrical signal is at a frequency of 235MHz corresponding to the radial vibrational mode of the silicon microdisk.