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McKelvey School of Engineering

Brown School

ESE Seminar: Preliminary Oral Exam: Jie Liao

Tuesday, July 20, 2021 | 3:15 PM - 5:15 PM

High-quality optical whispering-gallery-mode (WGM) resonators can trap photons in micro scales through total internal reflection. Light is confined and continuously recirculated along the curved boundary within the cavity at the resonant wavelength. The advances in WGM resonators for various applications have shown a promising future in many cutting-edge technologies, including non-Hermitian and topological photonics, nonlinear optics, low threshold lasers, and optical sensors. WGM sensors have attracted a lot of interest in recent years due to their exceptional properties such as small mode volume, high time-resolution, and high quality factor (Q factor). The ultra-high sensitivity of WGM sensors shows great potential in probing physical quantities and phenomena, as well as the detection of nanoparticles and molecules. With their diversity in different sensor geometries, materials, sensing mechanisms, surface modifications, and device integration techniques, WGM sensors would become high-performance sensing platforms enabling the discovery of new physics and breakthroughs in biosensing and medical diagnosis.
In this presentation, I will introduce novel sensing techniques and integration strategies of WGM sensors and propose several applications related to our sensors with high Q factors. First, I will introduce an optical WGM barcode technique involving simultaneous monitoring of the patterns of multiple modes that can provide a direct temperature readout from the spectrum. The measurement relies on the patterns of multiple modes in the WGM spectrum instead of the changes of a particular mode. It can provide us with more information than the single-mode spectrum, such as the precise measurement of actual temperatures. Second, I will introduce our study exploring the integration of WGM devices using polydimethylsiloxane (PDMS). The PDMS packaging not only provides the WGM device with better robustness and compactness but also improves the humidity resistance significantly. Third, I will talk about various sensing applications of WGM sensors, including multi-parameter displacement sensing, pulse sensing, respiration monitoring, mechanical wave detection, and acoustic wave detection.


Event Type



McKelvey School of Engineering


Science & Technology

Electrical & Systems Engineering
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