Properties of optical microsensor based on observation of whispering-gallery modes

Abstract

Formulae for the intensity of the resonant spontaneous electric-dipole emission are derived in the framework of classical electrodynamics and quantum optics making allowance for inhomogeneous light absorption. Using these formulas, the physical backgrounds of a micrometer-sized optical sensor exploiting the properties of the whispering-gallery modes (WGMs) are studied. The role of the evanescent WGM's field in the considered optical effects is examined.