Particle Sensing And Mode Controlling Based On Rayleigh Scattering

Based on the whispering gallery mode(WGM)microcavity platform,we can transmit and modulate optical information.Among them,nanoparticle sensing with mode splitting and linewidth broadening analysis is one of the popular research directions of the whispering gallery mode optical platform.In this paper,we study the coupling theory of the whispering gallery mode microcavity by using a model of the whispering gallery mode microcavity and investigate the mode control and the exceptional points(EPs)of nanoparticles in the evanescent field of the whispering gallery mode microcavity.And the following results are achieved:1.In the aspect of whispering gallery mode microcavity sensing,the control of the optical mode is the key to realize the whispering gallery mode microcavity sensors.In this paper,the whispering gallery mode microcavity and the spherical and ellipsoidal nanoparticles in its evanescent field are studied.The mode generation and modulation in the microcavity are further studied by controlling the axial direction of the ellipsoidal nanoparticle.The mode splitting and linewidth broadening caused by the scattering of ellipsoidal nanoparticle are related to the axial direction of the ellipsoidal nanoparticle.In this scheme,the coupling strength and mode dissipation can be adjusted by controlling the axial direction of the ellipsoidal particle.2.In the aspect of the research of the exceptional points(EPs)of microcavity,we use the properties of the ellipsoidal particle to control the exceptional points of the microcavity system.In the microcavity system with nanoparticles,we further achieve the modulation of the exceptional points of microcavity system by controlling the ellipsoidal particle axes and observing the spectrum.This provides a new scheme for studying the exceptional points of the microcavity system.