Nanowerk May 10, 2019
The ability to detect small nano-particles and eventually single molecules remains a challenge. Current attempts focus on microring or microtoroid resonators which enhance the interaction between light and the molecule to be detected. The sensitivity of these devices, however, is limited by their fundamental physics. A team of researchers in the US (Michigan Technological University, University of Central Florida, Pennsylvania State University) propose a type of sensor based on the new notion of exceptional surfaces: surfaces that consist of exceptional points. However, the enhanced sensitivity of exceptional point-based sensors is very sensitive to unavoidable fabrication errors and undesired environmental variations. The team’s proposal alleviates most of these problems by introducing a new system that has the same enhanced sensitivity reported in previous work, while at the same time robust against most of the uncontrivable experimental uncertainty…read more. TECHNICAL ARTICLE
The microring resonator is coupled to a waveguide with an end mirror that partially reflects light, which in turn enhances the sensitivity. Credit: Ramy El-Ganainy and Qi Zhong