Theory of the nanoparticle-induced frequency shifts of whispering-gallery-mode resonances in spheroidal optical resonators
arXiv:1504.03399 · doi:10.1103/PhysRevA.92.013842
Abstract
Nanoparticle-induced modifications of the spectrum of whispering-gallery-modes (WGM) of optical spheroidal resonators are studied theoretically. Combining an ab initio solution of a single resonator problem with a dipole approximation for the particle, we derive simple analytical expressions for frequencies and widths of the particle-modified resonances, which are valid for resonators with moderate deviations from the spherical shape. The derived expressions are used to analyze spectral properties of the resonator-particle system as functions of the particle's position, the size of the resonators and the characteristics of WGMs. The obtained results are shown to agree well with available experimental data. It is also demonstrated that the particle-induced spectral effects can be significantly enhanced by careful selection of resonator's size, refractive index and other experimental parameters. The results presented in the paper can be useful for applications of WGM resonators in biosensing, cavity QED, optomechanics and others.
References in corpus (8)
- Magnetic light
- Detecting single viruses and nanoparticles using whispering gallery microlasers
- Controlled coupling of counterpropagating whispering-gallery modes by a single Rayleigh scatterer: a classical problem in a quantum optical light
- Raman-gain induced loss-compensation in whispering-gallery-microresonators and single-nanoparticle detection with whispering-gallery Raman-microlasers
- Rayleigh scattering, mode coupling, and optical loss in silicon microdisks
- Demonstration of mode splitting in an optical microcavity in aqueous environment
- Ultra-sensitive detection of mode splitting in active optical microcavities
- Optical coupling of fundamental whispering gallery modes in bi-spheres