Whispering Gallery Mode Devices: New Paradigms in Optical Sensors

Abraham Qavi, Xuefeng Jiang, Steven He, Guangming Zhao, Weijan Chen, Linhua Xu, Xiangyi Xu, Yihang Li, Changqing Wang, Lan Yang
Washington University in St. Louis, Missouri, United States

Keywords: Optical Sensors, Biosensing, Photonics

Optical Whispering Gallery Mode (WGM) microresonators are a class of high-Q devices, which significantly enhance the interaction between light and matter. These devices offer numerous benefits compared to other sensor systems, including: (1) real-time, continuous measurements, (2) small foot-print, reducing the sample volume required (3) scalable and inexpensive manufacturing techniques commonly used by the semi-conductor industry, and (4) the ability to be integrated with other electronics. Our group has leveraged WGM sensors for a wide array of applications, including the detection of infrared light, gas sensing, photo-acoustic imaging, analysis of biological molecules, and nanoparticle detection & sizing. We have also combined our WGM sensors with Raman spectroscopy, to develop new, hybrid, optical detection techniques. The ability to integrate WGMs with other technologies has also led to a hand-held WGM platform that will allow us to release the power of high-Q WGM resonator technologies to a wide range of applications. In addition to sensing applications, we have developed techniques to fabricate WGM devices out of a broad range of materials, including titanium dioxide, rare-earth doped silica, PDMS, and biocompatible silk. These new materials will open new sensing applications and opportunities for these devices.