Review of effects involving coresonant whispering-gallery modes of orthogonal polarization

Abstract

Coresonant, but orthogonally polarized, whispering gallery modes can couple to each other via the optical spin-orbit interaction. This cross-polarization coupling (CPC) can result in coupled-mode-induced transparency, attenuation, or Autler-Townes splitting. By fitting observed throughput spectra to a numerical model, the CPC strength can be determined and found to agree with the theory. The throughput response to input amplitude modulation provides an independent method of measuring the CPC strength. Observation and fitting of throughput spectra of both polarizations confirms that CPC is nonreciprocal. Induced transparency and attenuation can be observed even without CPC, by utilizing mode superposition. All these effects will be reviewed.