Trace Ammonia Detection Based on Near-Infrared Fiber-Optic Cantilever-Enhanced Photoacoustic Spectroscopy  

作　　者：Min GUO Ke CHEN Zhenfeng GONG Qingxu YU 

机构地区：[1]School of Optoelectronic Engineering and Instrumentation Science,Dalian University of Technology,Dalian 116024,China

出　　处：《Photonic Sensors》2019年第4期293-301,共9页光子传感器（英文版）

基　　金：This work is supported by the Fundamental Research Funds for the Central Universities[Grant No.DUT 18RC(4)040].

摘　　要：A trace ammonia(NH3)detection system based on the near-infrared fiber-optic cantilever-enhanced photoacoustic spectroscopy(CEPAS)is proposed.A fiber-optic extrinsic Fabry-Perot interferometer(EFPI)based cantilever microphone has been designed to detect the photoacoustic pressure signal.The microphone has many advantages,such as small size and high sensitivity.A near-infrared tunable erbium-doped fiber laser(EDFL)amplified by an erbium-doped fiber amplifier(EDFA)is used as a photoacoustic excitation light source.To improve the sensitivity,the photoacoustic signal is enhanced by a photoacoustic cell with a resonant frequency of 1624 Hz.When the wavelength modulation spectroscopy(WMS)technique is applied,the weak photoacoustic signal is detected by the second-harmonic detection technique.Trace NH3 measurement experiments demonstrate that the designed fiber-optic CEPAS system has a linear response to concentrations in the range of 0 ppm‒20 ppm at the wavelength of 1522.448 nm.Moreover,the detection limit is estimated to be 3.2 ppb for a lock-in integration time of 30 s.

关 键 词：Trace gas detection photoacoustic spectroscopy cantilever microphone fiber-optic Fabry-Perot interferometer near-infrared laser 

分 类 号：TN2[电子电信—物理电子学]