Application of Micro Quartz Tuning Fork in Trace Gas Sensing by Use of Quartz-Enhanced Photoacoustic Spectroscopy

Haoyang Lin; Zhao Huang; Ruifeng Kan; Huadan Zheng; Yihua Liu; Bin Liu; Linpeng Dong; Wenguo Zhu; Jieyuan Tang; Jianhui Yu; Zhe Chen; Frank K Tittel

doi:10.3390/s19235240

Application of Micro Quartz Tuning Fork in Trace Gas Sensing by Use of Quartz-Enhanced Photoacoustic Spectroscopy

Sensors (Basel). 2019 Nov 28;19(23):5240. doi: 10.3390/s19235240.

Authors

Haoyang Lin¹, Zhao Huang¹, Ruifeng Kan², Huadan Zheng^{1

3}, Yihua Liu¹, Bin Liu⁴, Linpeng Dong^{1

3}, Wenguo Zhu^{1

3}, Jieyuan Tang^{1

3}, Jianhui Yu^{1

3}, Zhe Chen^{1

3}, Frank K Tittel⁵

Affiliations

¹ Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Department of Optoelectronic Engineering, Jinan University, Guangzhou 510632, China.
² State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
³ Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Jinan University, Guangzhou 510632, China.
⁴ School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China.
⁵ Department of Electrical and Computer Engineering, Rice University, Houston, TX 77005, USA.

Abstract

A novel quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor based on a micro quartz tuning fork (QTF) is reported. As a photoacoustic transducer, a novel micro QTF was 3.7 times smaller than the usually used standard QTF, resulting in a gas sampling volume of ~0.1 mm³. As a proof of concept, water vapor in the air was detected by using 1.39 μm distributed feedback (DFB) laser. A detailed analysis of the performance of a QEPAS sensor based on the micro QTF was performed by detecting atmosphere H₂O. The laser focus position and the laser modulation depth were optimized to improve the QEPAS excitation efficiency. A pair of acoustic micro resonators (AmRs) was assembled with the micro QTF in an on-beam configuration to enhance the photoacoustic signal. The AmRs geometry was optimized to amplify the acoustic resonance. With a 1 s integration time, a normalized noise equivalent absorption coefficient (NNEA) of 1.97 × 10^-8 W·cm^-1·Hz^-1/2 was achieved when detecting H₂O at less than 1 atm.

Keywords: acoustic detection module; photoacoustic spectroscopy; quartz tuning fork; quartz-enhanced photoacoustic spectroscopy.

Abstract

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