Zhao Xinyu, Qi Hongchao, Xu Yufu, Li Chenxi, Guo Min, Zhao Jikuan, Cui Dongyu, Chen Ke
Opt Lett. 2023 Sep 1;48(17):4558-4561. doi: 10.1364/OL.498908.
We design a photoacoustic (PA) SO sensor based on the coupling of a differential photoacoustic cell (DPAC) and cost-effective UV-LED, which realized the dynamic monitoring of SO gas at the ppb level. Aiming at the limitation of UV-LED divergence, a light source combination module with high condensing efficiency was devised based on a lens through theoretical derivation and experimental analysis. The PA signal with the optimum matching of the lens was 20-times larger than the direct coupling of the UV-LED. Due to the excellent beam collimation effect of the lens assembly, the background interference was only 1 ppm. In addition, the DPAC gathered the merits of doubling the PA signal and reducing the flow noise interference. The analysis of Allan-Werle deviation showed that the detection limit of SO was 1.3 ppb with the averaging time of 100 s.
我们设计了一种基于差分光声池（DPAC）与经济高效的紫外发光二极管（UV-LED）耦合的光声（PA）SO传感器，实现了对ppb级SO气体的动态监测。针对UV-LED发散的局限性，通过理论推导和实验分析，设计了一种基于透镜的高聚光效率光源组合模块。透镜实现最佳匹配时的PA信号比UV-LED直接耦合时大20倍。由于透镜组件具有出色的光束准直效果，背景干扰仅为1 ppm。此外，DPAC兼具使PA信号加倍和降低流动噪声干扰的优点。Allan-Werle偏差分析表明，SO的检测限为1.3 ppb，平均时间为100 s。
