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Indexed by:期刊论文

Date of Publication:2020-11-01

Journal:OPTICS AND LASERS IN ENGINEERING

Included Journals:SCIE

Volume:134

ISSN No.:0143-8166

Key Words:Photoacoustic spectroscopy; Trace gas detection; Fabry-Perot; Parylene-C diaphragm

Abstract:A low-frequency photoacoustic (PA) sensor based on Parylene-C diaphragm for space-limited trace gas detection is presented. The overall structure of the sensor head includes a cylindrical brass shell, a Parylene-C diaphragm, and a PA cavity regarded as the Fabry-Perot (F-P) cavity as well. The volume of the PA cavity is only 74 mu L. A distributed feedback (DFB) laser is used as an acoustic excitation source. The deflection of the Parylene-C diaphragm was measured by using fiber-optic white-light interference (WLI) method to obtain the PA pressure signal. The PA sensor is used for acetylene (C2H2) detection with a detection limit of 88.4 parts-per-billion (ppb) when the lock-in integration time is 1 s.