Mode localization in plasmonic optomechanical resonators for ultrasensitive infrared sensing

Uncooled infrared thermal detectors are gaining increasing attention owing to their ability to operate at room-temperature and their low cost. This study proposes a plasmonic optomechanical resonator for ultrasensitive long-wave infrared wave sensing based on mode localization mechanism. The mode-localized effect confines the plasmonic energy in the resonators and induces a significant modal amplitude shift through infrared irradiation, thus achieving highly sensitive detection. The results show that the detection sensitivity can reach 1.304 /mW, which is three-order improvement compared to the frequency-shift sensing metrics. The research provides a new approach to further improve the detection sensitivity of uncooled infrared sensors.