Chen Weipeng, Qiao Shunda, Lang Ziting, Jiang Jiachen, He Ying, Shi Yiwei, Ma Yufei
Opt Lett. 2023 Aug 1;48(15):3989-3992. doi: 10.1364/OL.497685.
In this Letter, a hollow waveguide (HWG)-based light-induced thermoelastic spectroscopy (LITES) gas sensing is proposed. An HWG with a length of 65 cm and inner diameter of 4 mm was used as the light transmission medium and gas chamber. The inner wall of the HWG was coated with a silver (Ag) film to improve reflectivity. Compared with the usually used multi-pass cell (MPC), the HWG has many advantages, such as small size, simple structure and fast filling. Compared with a hollow-core anti-resonant fiber (HC-ARF), the HWG has the merits of easy optical coupling, high system stability, and wide transmission range. A diode laser with output wavelength of 1.53 µm and a quantum cascade laser (QCL) with output wavelength of 4.58 µm were selected as the sources of excitation to target acetylene (CH) and carbon monoxide (CO), respectively, to verify the performance of the HWG-based LITES sensor in the near-infrared and mid-infrared regions. The experimental results showed that the HWG-based LITES sensor had a great linear responsiveness to the target gas concentration. The minimum detection limit (MDL) for CH and CO was 6.07 ppm and 98.66 ppb, respectively.
在本信函中，提出了一种基于空心波导（HWG）的光致热弹性光谱（LITES）气体传感技术。使用一根长度为65 cm、内径为4 mm的HWG作为光传输介质和气室。HWG的内壁涂有银（Ag）膜以提高反射率。与常用的多程池（MPC）相比，HWG具有许多优点，如尺寸小、结构简单和充气速度快。与空心反谐振光纤（HC-ARF）相比，HWG具有易于光耦合、系统稳定性高和传输范围宽等优点。分别选择输出波长为1.53 µm的二极管激光器和输出波长为4.58 µm的量子级联激光器（QCL）作为激发源，以检测乙炔（CH）和一氧化碳（CO），从而验证基于HWG的LITES传感器在近红外和中红外区域的性能。实验结果表明，基于HWG的LITES传感器对目标气体浓度具有良好的线性响应。CH和CO的最低检测限（MDL）分别为6.07 ppm和98.66 ppb。
