Optically activated vibrations in a micromachined silica structure

A microminiature bridge of silicon dioxide, fabricated using anisotropic etch techniques on a silicon substrate, has been set into mechanical vibration by direct interaction with a low-power laser beam. The displacement sensitivity and frequency response of the optomechanical interaction have been characterised using optical interferometry. The implications of the results for the development of radically new optical sensors are discussed.