Li, Sherry

Project title: Application on high-Q silica microcavities: portable bio-monitor

Department: Electrical and Computer Engineering

Faculty supervisor: Dr. Tao Lu

"A cavity resonator is a system where waves exist in a hollow space and exhibits resonant behavior. When it oscillates at resonant frequency, photons traveling along the sphere are coherently constructed then constructive lights generate intense powers. Microcavities are operated in the same principle as conventional optical cavities but in smaller dimensions.

Optical whispering gallery mode (WGM) microresonators are high-Q, label-free and low-volumes micro-sphere resonators which confine resonant photons travelling along the edge of cavity. Due to continuous total internal reflection, WGM resonators are able to enhance light-matter interaction and furthermore to achieve ultra-sensitive detections down to single molecules. Different molecules are polarized differently when binding to a microsphere surface within a wave field of a MGW. Due to the bindings, the WGM path lengths are increased and therefore resonance frequency shifts are induced. By detecting different resonance frequency shifts caused by different bindings, different types of molecules can be identified."