Li Yifan, Liu Lixian, Zhao Liang, Zhang Xueshi, Zhang Le, Sun Jialiang, Huan Huiting, Liang Yize, Zhang Jiyong, Shao Xiaopeng, Mandelis Andreas, Voti Roberto Li
School of Optoelectronic Engineering, Hangzhou Insitute of Technology and State Key Laboratory of Electromechanical lntegrated Manufacturing of High-performance Electronic Equipment, Xidian University, Xi'an 710071, China.
Center for Advanced Diffusion-Wave and Photoacoustic Technologies (CADIPT), Department of Mechanical and Industrial Engineering, and Institute for Advanced Non, Destructive and Non-Invasive Diagnostic Technologies (IANDIT), University of Toronto, Toronto M5S 3G8, Canada.
Photoacoustics. 2024 Nov 28;41:100669. doi: 10.1016/j.pacs.2024.100669. eCollection 2025 Feb.
A compact and robust optical excitation photoacoustic sensor with a self-integrated laser module excitation and an optimized differential resonator was developed to achieve high sensitivity and full linear range detection of carbon dioxide (CO) based on dual modes of wavelength modulated photoacoustic spectroscopy (WMPAS) and resonant frequency tracking (RFT). The integrated laser module equipped with three lasers (a quantum cascade laser (QCL), a distributed feedback laser (DFB) and a He-Ne laser) working in a time-division multiplexing mode was used as an integrated set of spectroscopic sources for detection of the designated concentration levels of CO. With the absorption photoacoustic mode, the WMPAS detection with the QCL and DFB sources was capable of CO detection at concentrations below 20 %, yielding a noise equivalent concentration (NEC) as low as 240 ppt and a normalized noise equivalent absorption coefficient (NNEA) of 4.755 × 10 W cm/√Hz, and dynamic range as great as 11 orders of magnitude. Higher concentration detection ranges (20 %-100 %) of CO were investigated using the RFT mode with an amplitude-stabilized He-Ne laser and a mechanical chopper. With the dual modes of WMPAS and RFT, the optical excitation sensor achieved full-range CO detection, with an R² ≥ 0.9993 and a response time of 5 seconds. The compact and full-range CO sensor combines the advantages of WMPAS and RFT and offers a solution for high sensitivity, linearity and full-range CO detection.
基于波长调制光声光谱（WMPAS）和共振频率跟踪（RFT）的双模式，开发了一种紧凑且坚固的光激发光声传感器，该传感器具有自集成激光模块激发和优化的差分谐振器，以实现对二氧化碳（CO）的高灵敏度和全线性范围检测。配备有三个以时分复用模式工作的激光器（一个量子级联激光器（QCL）、一个分布反馈激光器（DFB）和一个氦氖激光器）的集成激光模块被用作检测指定浓度水平CO的光谱源集成组。在吸收光声模式下，使用QCL和DFB源进行的WMPAS检测能够检测浓度低于20%的CO，产生低至240 ppt的噪声等效浓度（NEC）和4.755×10 W cm/√Hz的归一化噪声等效吸收系数（NNEA），动态范围高达11个数量级。使用具有振幅稳定的氦氖激光器和机械斩波器的RFT模式研究了更高浓度范围（20%-100%）的CO检测。通过WMPAS和RFT的双模式，光激发传感器实现了全范围的CO检测，R²≥0.9993，响应时间为5秒。这种紧凑的全范围CO传感器结合了WMPAS和RFT的优点，为高灵敏度、线性和全范围CO检测提供了一种解决方案。
