▎ 摘　　要

NOVELTY - Plasmonic gas sensor based on D-shaped fiber graphene heterojunction comprises D-shaped area of D-shaped optical fiber is covered with a gold-graphene-gold heterojunction. A stabilized voltage source is connected to two gold poles of heterojunction of D-shaped fiber through two probes to provide a stable connection voltage of 0-20V for both ends of graphene. The electrical signal output by photodetector is connected with probe connected to negative pole of voltage stabilizer. The aim is to precisely control voltage changes across graphene. The D-shaped area of D-shaped optical fiber is covered with a gold-graphene-gold heterojunction. The broadband tunable laser is connected to polarization controller 2 and fiber amplifier in turn. The input of balanced detector consists of two signals. The input of lock-in amplifier is respectively connected to output end of the balanced detector and other output end of optical splitter, and its output is connected to oscilloscope. USE - Used as plasmonic gas sensor based on D-shaped fiber graphene heterojunction. ADVANTAGE - The sensor: combines two-dimensional material optoelectronics, micro-nano processing technology and signal detection and extraction technology, relying on the integration of gold and graphene gold heterostructures on the D-shaped optical fiber polishing surface; utilizes the extremely high field locality of graphene plasmons and the sensitivity to refractive index changes; realizes the ultra-high sensitivity all-fiber gas sensor with the coexistence of the plasmon surface field and the optical waveguide wave field with high controllability and high sensitivity; can realize all-optical excitation and electronic photon cross regulation; and has extremely high application value in biochemical sensing fields i.e. environmental monitoring and gas detection. DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the plasmonic gas sensor based on D-shaped fiber graphene heterojunction.