High Q-factor, ultrasensitivity slot microring resonator sensor based on chalcogenide glasses
Xuelei Zhang, Chenfeng Zhou, Ye Luo, Zhen Yang, Wei Zhang, Lan Li, Peipeng Xu, Peiqing Zhang, Tiefeng Xu
Abstract
In this article, the chalcogenide slot waveguide is theoretically studied, and the highest power confinement factors of the slot region and the cladding region are obtained to be 36.3% and 56.7%, respectively. A high-sensitivity chalcogenide slot microring resonator sensor is designed and fabricated by electron-beam lithography and dry etching. The structure increases the sensitivity of the sensor compared with the conventional evanescent field waveguide sensor. The cavity has achieved a quality factor of 1 × 10 4 by fitting the resonant peaks with the Lorentzian profile, one of the highest quality factors reported for chalcogenide slot microring resonators. The sensor sensitivity is measured to be 471 nm/RIU, which leads to an intrinsic limit of detection of 3.3 × 10 −4 RIU.