Zhao Xinyu, Qi Hongchao, Wang Heng, Wang Xiaona, Guo Min, Peng Wei, Chen Ke
School of Optoelectronic Engineering and Instrumentation Science, Dalian University of Technology, Dalian, Liaoning 116024, China.
School of Physics, Dalian University of Technology, Dalian, Liaoning 116024, China.
Anal Chem. 2024 Apr 9;96(14):5554-5559. doi: 10.1021/acs.analchem.4c00005. Epub 2024 Mar 28.
A miniaturized optical fiber photoacoustic gas sensor enhanced by dense multibutterfly spots is reported for the first time. The principle of space light transmission of neglecting paraxial approximation is theoretically analyzed for designing a dense multibutterfly spots-based miniature multipass cell. In a multipass photoacoustic tube with a diameter of 16 mm, the light beam is reflected about a hundred times. The light spots on the mirror surfaces at both ends of the photoacoustic tube form a dense multibutterfly distribution. The volume of the micro multipass gas chamber is only 5.3 mL. An optical fiber cantilever based on F-P interference is utilized as a photoacoustic pressure detector. Compared with that of the single-pass structure, the gas detection ability of the photoacoustic system with dense multibutterfly spots is improved by about 50 times. The proposed miniaturized sensor realizes a detection limit of 3.4 ppb for CH gas with an averaging time of 100 s. The recognized coefficients of minimum detectable absorption (α) and normalized noise equivalent absorption are 1.9 × 10 cm and 8.4 × 10 W cm Hz, respectively.
首次报道了一种由密集多蝶形光斑增强的微型光纤光声气体传感器。为设计基于密集多蝶形光斑的微型多程池，从理论上分析了忽略傍轴近似的空间光传输原理。在直径为16毫米的多程光声管中，光束被反射约一百次。光声管两端镜面上的光斑形成密集的多蝶形分布。微型多程气室的体积仅为5.3毫升。基于F-P干涉的光纤悬臂被用作光声压力探测器。与单通道结构相比，具有密集多蝶形光斑的光声系统的气体检测能力提高了约50倍。所提出的微型传感器实现了对CH气体3.4 ppb的检测限，平均时间为100秒。最小可检测吸收（α）和归一化噪声等效吸收的公认系数分别为1.9×10 cm和8.4×10 W cm Hz。
