[Nano Letters] Graphene enhanced Brillouin optomechanical microresonator for ultra-sensitive gas det
Chemical sensing is one of the most important applications of nanoscience, whose ultimate aim is to seek higher sensitivity. In recent years, graphene with intriguing quantum properties has spurred dramatic advances ranging from materials science to optoelectronics and mechanics, showing its potential to realize individual molecule solid-state sensors. However, for optical sensing, the single atom thickness of graphene greatly limits the light-graphene interaction, bottlenecking their performances. Here we demonstrate a novel approach based on the forward phase-matched Brillouin optomechanics in a graphene inner-deposited high Q (> 2×106) microfluidic resonator, expanding the ‘electron-photon’ interaction in conventional graphene optical devices to the ‘electron-phonon-photon’ process. The molecular adsorption induced surface elastic modulation in graphene enables the Brillouin optomechanical modes (mechanical Q ≈ 43,670) extremely sensitive (200 kHz/ppm) in ammonia gas detection, achieving a noise equivalent detection limit down to 1 ppb and an unprecedented dynamic range over five orders-of-magnitude, with fast response. This work provides a new platform for the researches of graphene-based optomechanics, nano-photonics and optical sensing.
Baicheng Yao, Caibin Yu, Yu Wu, Shu-Wei Huang, Han Wu, Yuan Gong, Yuanfu Chen, Yanrong Li, Chee Wei Wong, Xudong Fan, and Yunjiang Rao Nano Lett., Just Accepted Manuscript DOI: 10.1021/acs.nanolett.7b02176 Publication Date (Web): July 14, 2017 Copyright © 2017 American Chemical Society