Date Published: March 15, 2024
A recent paper published by Light: Science & Applications, a Nature sub-journal with impact factor 19.5, in March 2024, titled "Ultra-high-Q free-space coupling to microtoroid resonators" focuses on Whispering gallery mode (WGM) microtoroid resonators. WGM are extremely sensitive biochemical sensors capable of detecting single molecules. However, their practical use is limited by the fragile and precise nature of the optical fiber coupling method. This research introduces a new method of free-space coupling using a long working distance objective lens and a digital micromirror device, achieving high sensitivity and eliminating the need for precise fiber positioning, which could pave the way for real-world applications of these sensors. Read the full abstract.
First author of the paper is Sartanee Suebka, PhD Student under the advisement of Judy Su, Associate Professor of Optical Sciences, who is the senior author on the paper. Euan McLeod, Associate Professor of Optical Sciences, is also a co-author on the paper. Learn more about this work in a recent BioPhotonics news article.
(a): An objective lens is used to couple free space light (red beam) into the microtoroid. The resonant scatter light is collected at the opposite edge, as indicated by the orange beam. (b): Scanning electron micrograph of a microtoroid resonator (SEM image). (c): Microtoroid resonance wavelength at different temperatures. (d): Resonance wavelength shift vs temperature. A linear fit is shown as a solid black line. Courtesy of Sartanee Suebka, Euan McLeod, and Judith Su.
Sartanee Suebka, Euan McLeod, and Judith Su