Abstract: In recent years，the Whispering Gallery Mode ( WGM) optical resonators have attracted

wide atten- tion from scholars all over the world due to their super high quality factor ( Q

value) and small model volume. They play an important role in both civil and military devices. At

present，the research of whispering gallery mode optical resonator mainly includes microwave

photonics，nonlinear optics and inertial navigation devices. In this paper，the research status of

whispering gallery mode resonators in various countries is summarized and summarized. It will be

discussed from six aspects: characteristic parameters，material selection，optical

coupling，shape，application and prospect. The aim is to present the achievements，challenges and

future development direction of echo wall mode optical resonator.

Key words: WGM, optical resonator, optical quality factor