Femtogram scale nano-optomechanical resonators in water

Abstract

A femtogram scale nanobeam optomechanical crystal (OMC) resonator operating in water is designed and demonstrated. The thermomechanical motion of the highly damped mechanical resonance in water can be resolved by the sensitive cavity optomechanical readout. The present device has an estimated mass sensitivity at the attogram level (1.33 ag/VHz) in water. A silicon nitride nanobeam OMC resonator with high optical Q-factor operating at visible wavelength is designed to improve the mass sensitivity.