A multi-pass differential photoacoustic spectrometer at 1064 nm for ambient aerosol absorption

作者：Jie Chen, Xianmei Qian, Wenyue Zhu, Qiang Liu, Jianjie Zheng, Tao Yang, Tengfei Yang · 发表于：Photoacoustics · 年份：2025 · DOI：10.1016/j.pacs.2025.100769 · 被引用次数：2 · 研究领域：Medicine

Accurate atmospheric aerosol absorption measurements are critical for advancing our understanding of global climate effects and reginal meteorological processes. In this paper, a multi-pass differential photoacoustic spectrometer (MP-DPAS) worked at 1064 nm, was developed for the in-situ measurement of atmospheric aerosol absorption coefficients (Abs). By employing the multi-pass configuration, 22 reflections of the incident laser were achieved, thereby the photoacoustic signal was enhanced by a factor of ten. Meanwhile, the differential configuration not only suppress background noise but also amplifies the signal by a factor of two. Consequently, the MP-DPAS achieved a minimum detection limit of 0.05 Mm−1 within an integration time of 110 s and a precision of 1.4 Mm−1. The accuracy of the MP-DPAS was validated by comparing the measured Abs with the calculated Abs of Mie scattering theory and the variation of particle size distribution measured by SMPS (Scanning Mobility Particle Sizer).