Fiber-Amplifier-Enhanced QEPAS Sensor for Simultaneous Trace Gas Detection of NH3 and H2S

Sensors

Hongpeng Wu¹  Lei Dong²  Xiaoli Liu¹  Huadan Zheng¹  Xukun Yin¹  Weiguang Ma¹  Lei Zhang¹  Wangbao Yin¹  Suotang Jia¹ 

[1] State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy, Shanxi University, Taiyuan 030006, China;

关键词: quartz enhanced photoacoustic spectroscopy;    near-infrared distributed feedback laser;    erbium doped fiber amplifier;    modulation cancelation method;    multi-component traces gas detection;   

DOI  :  10.3390/s151026743

来源: mdpi

【 摘 要 】

A selective and sensitive quartz enhanced photoacoustic spectroscopy (QEPAS) sensor, employing an erbium-doped fiber amplifier (EDFA), and a distributed feedback (DFB) laser operating at 1582 nm was demonstrated for simultaneous detection of ammonia (NH₃) and hydrogen sulfide (H₂S). Two interference-free absorption lines located at 6322.45 cm⁻¹ and 6328.88 cm⁻¹ for NH₃ and H₂S detection, respectively, were identified. The sensor was optimized in terms of current modulation depth for both of the two target gases. An electrical modulation cancellation unit was equipped to suppress the background noise caused by the stray light. An Allan-Werle variance analysis was performed to investigate the long-term performance of the fiber-amplifier-enhanced QEPAS sensor. Benefitting from the high power boosted by the EDFA, a detection sensitivity (1σ) of 52 parts per billion by volume (ppbv) and 17 ppbv for NH₃ and H₂S, respectively, were achieved with a 132 s data acquisition time at atmospheric pressure and room temperature.

【 授权许可】

CC BY   
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