Nonlinear and Quantum Optics with Whispering Gallery Resonators

TL;DR

This paper reviews the use of optical Whispering Gallery Mode resonators, highlighting their high quality factors, small mode volume, and tunability, which make them highly effective for nonlinear and quantum optical applications.

Contribution

It provides a comprehensive overview of recent advances, challenges, and future prospects in nonlinear and quantum optics utilizing WGM resonators.

Findings

High quality factors enable efficient nonlinear interactions.

WGM resonators are versatile across a wide wavelength range.

Potential for future quantum optical technologies.

Abstract

Optical Whispering Gallery Modes (WGMs) derive their name from a famous acoustic phenomenon of guiding a wave by a curved boundary observed nearly a century ago. This phenomenon has a rather general nature, equally applicable to sound and all other waves. It enables resonators of unique properties attractive both in science and engineering. Very high quality factors of optical WGM resonators persisting in a wide wavelength range spanning from radio frequencies to ultraviolet light, their small mode volume, and tunable in- and out- coupling make them exceptionally efficient for nonlinear optical applications. Nonlinear optics facilitates interaction of photons with each other and with other physical systems, and is of prime importance in quantum optics. In this paper we review numerous applications of WGM resonators in nonlinear and quantum optics. We outline the current areas of interest, summarize progress, highlight difficulties, and discuss possible future development trends in these areas.