Auxiliary-Cavity-Induced Ultrasensitive and Ultrahigh-Resolution Biomolecule Mass Sensing in a Hybrid Spinning Resonator System

Abstract

We theoretically demonstrate an ultrasensitive and ultrahigh-resolution biomolecule mass sensing based on a spinning resonator system, which includes a spinning whispering-gallery-mode (WGM) optomechanical cavity and an auxiliary optical cavity. When the WGM cavity is spinning along the clockwise or counterclockwise direction, the cavity field will undergo different Sagnac effect. If the Sagnac effect and the auxiliary optical cavity are simultaneously taken into consideration, not only the line width of the transmission spectrum is significantly squeezed, but also the transmission intensity will be extremely enhanced, which indicates an ultrasensitive and ultrahigh-resolution mass sensor. When the mass of external biomolecules (such as baculovirus or coronavirus) is deposited on the resonator, their mass can be determined by tracking the resonance frequency shifts in the transmission spectrum. Thus, our research can provide a method to classify kinds of viruses, especially can be used to identify 2019-nCoV.