Application of whispering gallery modes (WGM) in optical communications

In this article the basic information about the whispering gallery modes (WGM) concerning questions of mathematical description, properties of whispering gallery resonators (WGR), methods of radiation coupling into resonators, resonators manufacture methods, and possible applications in the field of optical communication systems is considered. A brief history of WGM discovery is presented, and the main properties and characteristics of such resonators and modes are discussed. The main goal of this work is to survey the field of WG modes that is becoming more and more attractive due to their interesting and exciting properties with accordance to possible applications in passive optical components development as well as in design of active components such as lasers and modulators.