Wavelength-sized GaAs optomechanical resonators with gigahertz frequency

摘要

We report on wavelength-sized GaAs optomechanical disk resonators showing ultrastrong optomechanical interaction. We observe optical transduction of a disk mechanical breathing mode with 1.4 GHz frequency and effective mass of ~2 pg. The measured vacuum optomechanical coupling rate reaches go=0.8 MHz, with a related differential optomechanical coupling factor g_(om)=485 GHzm. The disk Brownian motion is optically resolved with a sensitivity of 10~-17 m/ √Hz at room temperature and pressure.