This paper delves into the principles and applications of whispering-gallery mode (WGM) optical microcavities, with a focus on their use in advanced sensing technologies. Initially, it outlines the fundamental theories underpinning the WGM phenomenon, including optical properties and resonance behaviors within microcavities. Significant attention is given to the application of WGM microcavities in biosensing, particularly for label-free detection using mode splitting and frequency shift methods. Additionally, the paper proposes integrating theoretical frameworks such as Input-Output Theory and Photon-Resolved Floquet Theory (PRFT) to augment the functionality and sensitivity of these microcavities for real-time, high-precision diagnostic applications. Note: This work was published as a course paper under the author's alternative name, Likai Zhang.
Liang Zhang (Thu,) studied this question.