Abstract

The focus of this tutorial is the underlying physics of whispering gallery mode (WGM) optical resonators, and their applications in photonics, quantum optics, and fundamental physics. Whispering gallery mode resonators are optically transparent, axio-symmetric dielectric cavities that support extremely high quality factor (Q) modes with small mode volumes. These devices are small and can be manufactured in sizes ranging from a few tens of microns to a few millimeters. The combination of high-Q and small volume provides for a number of interesting processes in linear and nonlinear optics, allowing many applications. These includes, filters, modulators, low-threshold lasers, opto-mechanical oscillators, chaotic resonators, and high performance optical cavities suitable for cavity QED and search for variation of the fine structure constant. Recent developments in fabrication processes have produced extremely high Q’s (in excess of 10¹¹) in small volumes, spurring further interest and suggesting new applications.

© 2007 Optical Society of America