Whispering Gallery Mode Optical Microresonators: Structures and Sensing Applications

Whispering gallery mode resonators (WGMRs) have achieved significant results due to their unique properties such as extremely small mode volume, ultra-high quality (Q) factor, fast dynamic response, and ultra-high sensitivity. WGM is commonly used in theoretical physics research, nonlinear optics, optoelectronic devices, and the preparation of high-sensitivity sensors. This article briefly introduces the basic characteristics and sensing principle of WGM, the manufacturing method of WGMRs, and the sensing applications of microresonators in the fields of physics, chemistry, and biology. The detection limits of physical parameters and the detection sensitivity of biomolecules in recent decades are summarized. In addition, the advantages and disadvantages of different structures and the development trend of WGMRs applications are discussed.