Controlled coupling of counterpropagating whispering-gallery modes by a single Rayleigh scatterer: a classical problem in a quantum optical light

摘要

We present experiments where a single subwavelength scatterer is used toexamine and control the back-scattering induced coupling betweencounterpropagating high-Q modes of a microsphere resonator. Our measurementsreveal the standing wave character of the resulting symmetric and antisymmetriceigenmodes, their unbalanced intensity distributions, and the coherent natureof their coupling. We discuss our findings and the underlying classical physicsin the framework common to quantum optics and provide a particularly intuitiveexplanation of the central processes.