Graphene-Enhanced Brillouin Optomechanical Microresonator for Ultrasensitive Gas Detection

Abstract

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 interactions, 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 × 10) 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, nanophotonics, and optical sensing.

High-performance photoluminescence-based oxygen sensing with Pr-modified ZnO nanofibers

“…Based on the above sensing mechanisms, likely reasons for the superior oxygen sensing performance of the PZNF sample (cf. the ZNF sample) include: (1) The PZNF sample has a much larger S/V ratio (as shown in Fig. 2); and (2), as noted previously, Pr introduces additional active sites on the sample surface that facilitate oxygen adsorption [28−31].…”

Ultrasensitive sensing in air based on graphene-coated hollow core fibers

“…More importantly, our proposed RI sensor exhibits a high sensitivity of −365.9 dB/RIU at the refractive index of air. Provided an optical spectrum analyzer with a resolution of 0.001 dB [39], a high RI resolution of 2.73 × 10 −6 RIU can be achieved despite graphene based SPR [40] or ultra-high Q resonator [41] may be 10 −8…”

Solution-processed two-dimensional materials for ultrafast fiber lasers (invited)

“…For example, chemical vapor deposition (CVD) is a popular bottom-up method able to produce high-quality, large-area materials [44][45][46]. While CVD is used for applications such as integrated electronic devices [47,48] or transparent electrodes, for other applications such as solar cells, fuel cells, thermoelectric devices, or optical sensing systems [49][50][51][52], it is preferable to have the 2DMs dispersed in a liquid, which would make them easier to process and manipulate [53,54].…”