High-sensitivity all-optical PA spectrometer based on fast swept laser interferometry

Xuefeng Mao; Xiaoyan Ji; Yuting Tan; Hao Ye; Xiaofa Wang

doi:10.1016/j.pacs.2022.100391

High-sensitivity all-optical PA spectrometer based on fast swept laser interferometry

Photoacoustics. 2022 Aug 19:28:100391. doi: 10.1016/j.pacs.2022.100391. eCollection 2022 Dec.

Authors

Xuefeng Mao¹, Xiaoyan Ji¹, Yuting Tan¹, Hao Ye¹, Xiaofa Wang¹

Affiliation

¹ Chongqing University of Posts and Telecommunications, Chongqing 400065, China.

Abstract

A high-sensitivity all-optical photoacoustic spectroscopy based on fast swept laser interferometry is proposed to trace gas detection. The momentary cavity length of the fiber-optic Fabry-Perot microphone is demodulated by a fast swept-laser interferometry with an instantaneous frequency demodulation algorithm. The all-optical photoacoustic spectroscopy based on the designed microphone was tested for trace acetylene gas detection in the near-infrared region. The normalized noise equivalent absorption coefficient for acetylene gas is achieved to be 1.06 × 10^-9 cm^-1 W Hz^-1∕2.

Keywords: Fiber-optic acoustic sensor; Photoacoustic spectroscopy; Swept laser interferometry; Trace gas detection.