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Indexed by:期刊论文

Date of Publication:2019-02-18

Journal:OPTICS EXPRESS

Included Journals:SCIE、EI

Volume:27

Issue:4

Page Number:4648-4659

ISSN No.:1094-4087

Key Words:Cantilever beams; Gases; Laser excitation; Light sources; Nanocantilevers; Optical fibers; Remote control, Acoustic excitation; Conductive fibers; Detection limits; Erbium doped fibers; Integration time; Photoacoustic sensors; Real time response; Remote monitoring, Fiber optics

Abstract:We present a fiber-optic photoacoustic (PA) sensor for remote monitoring of gas micro-leakage. The gas sensing head is a miniature ferrule-top PA cavity with a cantilever beam. Gas diffuses into the cavity from the gap around the cantilever beam, and a small hole opens on the side wall. The volume of the optimized PA cavity is only 70 mu L. An erbium-doped fiber amplified laser is used as a light source of acoustic excitation. The PA pressure signal is obtained by measuring the deflection of the cantilever beam with a fiber-optic white-light interferometric readout. The experimental result of leaking acetylene (C2H2) gas measurement shows a real-time response of 11.2 s. A detection limit is achieved to be 20 ppb with a 1 s lock-in integration time and a 1 km conductive fiber. Since both the excitation light and probe light are transmitted by the optical fiber, the designed sensing system has the advantages of remote detection and intrinsic safety. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement