Sun Haiyue, Liu Yahui, He Ying, Qiao Shunda, Ma Yufei
National Key Laboratory of Laser Spatial Information, Harbin Institute of Technology, Harbin 150001, China.
Zhengzhou Research Institute, Harbin Institute of Technology, Zhengzhou 450008, China.
ACS Sens. 2025 Jun 27;10(6):4717-4724. doi: 10.1021/acssensors.5c01298. Epub 2025 Jun 3.
In this paper, a highly sensitive methane (CH) and acetylene (CH) dual-gas light-induced thermoelastic spectroscopy (LITES) sensor based on a novel dual-path multiring multipass cell (DPMR-MPC) and a circle-head quartz tuning fork (QTF) was demonstrated for the first time. A theoretical model was established on the basis of double concave spherical mirrors to realize a 14-interlaced-ring spot pattern in DPMR-MPC with an optical path length (OPL) of 26.7 m per path. The total optical path length to volume ratio (OPL/V) reached 22 cm. A circle-head QTF with a low resonant frequency of ∼9.5 kHz was adopted to enhance the LITES sensor's detection ability. A Raman fiber amplifier (RFA) and an erbium-doped fiber amplifier (EDFA) were employed to amplify the two-laser excitation source. When the integration time of the LITES sensor was increased to 100 s, the minimum detection limits (MDLs) for simultaneous detection of CH and CH could be improved to 50.9 and 6.64 ppb, respectively. Compared with the current spectroscopic techniques used for detecting multiple gases, the dual-gas LITES sensor in this study offers an obviously high detection sensitivity.
本文首次展示了一种基于新型双光路多环多程池（DPMR-MPC）和圆头石英音叉（QTF）的高灵敏度甲烷（CH）和乙炔（CH）双气体光致热弹性光谱（LITES）传感器。基于双凹球面镜建立了理论模型，以在DPMR-MPC中实现14交错环光斑图案，每条光路的光程长度（OPL）为26.7 m。总光程长度与体积比（OPL/V）达到22 cm。采用了低谐振频率约为9.5 kHz的圆头QTF来增强LITES传感器的检测能力。使用拉曼光纤放大器（RFA）和掺铒光纤放大器（EDFA）来放大双激光激发源。当LITES传感器的积分时间增加到100 s时，同时检测CH和CH的最低检测限（MDL）可分别提高到50.9和6.64 ppb。与目前用于检测多种气体的光谱技术相比，本研究中的双气体LITES传感器具有明显更高的检测灵敏度。
