Quartz-Enhanced Photothermal-Acoustic Spectroscopy for Trace Gas Analysis

Applied Sciences

Zhao Huang¹  Linpeng Dong²  Huadan Zheng²  Zhe Chen²  Wenguo Zhu²  Jianhui Yu²  Xiaohang Gu³  Jieyuan Tang³  Haoyang Lin³  Lei Dong⁴ 

[1] Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, China;Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Department of Optoelectronic Engineering, Jinan University, Guangzhou 510632, China;Key Laboratory of Optoelectronic Information and Sensing Technologies of Guangdong Higher Education Institutes, Jinan University, Guangzhou 510632, China;;State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Laser Spectroscopy &

关键词: photoacoustic spectroscopy;    photothermal spectroscopy;    gas sensing;    quartz tuning fork;   

DOI  :  10.3390/app9194021

来源: DOAJ

【 摘 要 】

A crystal quartz tuning fork (QTF) was used as a detector to collect and amplify laser-induced photoacoustic and photothermal waves simultaneously for trace chemical analysis. A wavelength modulation technique was applied to the proposed quartz-enhanced photothermal-acoustic spectroscopy (QEPTAS) to improve the detection signal-to-noise ratio. The QTF detector was exposed to the illumination of a near-infrared distributed feedback laser at distances of 1 m and 2 m to evaluate the QEPTAS sensor performance. The QEPTAS sensor performance was determined by detecting water vapor in ambient air using a near-infrared distributed feedback laser with a power of ~10 mW and a wavelength of 1.39 μm. With an optimized modulation depth of 0.47 cm⁻¹, the normalized noise equivalent absorption (NNEA) coefficients of 8.4 × 10⁻⁷ W·cm⁻¹·Hz^−1/2 and 3.7 × 10⁻⁶ W·cm⁻¹·Hz^−1/2 were achieved for a distance of 1 m and 2 m, respectively. The developed QEPTAS technique reduces the requirements for laser beam quality, resulting in a simple but robust sensor structure and demonstrates the ability of remote sensing of gas concentrations.

【 授权许可】

Unknown