Zhong Guoqiang, Ma Zhuo, Wang Junbo, Zheng Chuantao, Zhang Yu, Wang Yiding, Tittel Frank K
State Key Laboratory of Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012, China.
Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, TX 77005, USA.
Sensors (Basel). 2020 Feb 26;20(5):1266. doi: 10.3390/s20051266.
By contrast with the widely reported traditional two mirror-based Herriott cell, a three mirror-based dense pattern gas cell was proposed, of which the modeling and design were proven to be effective through a comparison between the simulated spot pattern and effective path length and those of the experimental results. A mechanical structure was designed to adjust the position/angle of the three mirrors for aligning the optical path. The experimentally measured reflection number was 60, resulting in an optical path length of ~11 m, which agrees well with the theoretical value of 10.95 m. Combined with a near-infrared laser with a center wavenumber located at an acetylene (CH) absorption line of 6521.2 cm, a CH sensor system was established to verify the feasibility of the three mirror-based gas cell. Assisted by a data acquisition (DAQ) card, a LabVIEW platform was developed to generate the drive signal of the laser and acquire the second harmonic (2) signal from the output of the detector. Through Allan variance analysis, the limit of detection (LoD) of the sensor system is 4.36 ppm at an average time of 0.5 s; as the average time exceeds 10 s, the LoD is <1 ppm. The proposed model and design of the three mirror-based gas cell can be used to realize similar gas cells with different absorption path lengths for gas detection based on infrared absorption spectroscopy.
与广泛报道的基于传统双镜的赫里奥特池相比，提出了一种基于三镜的密集型气室，通过模拟光斑图案和有效光程与实验结果的比较，证明了其建模和设计是有效的。设计了一种机械结构来调整三个镜子的位置/角度以对准光路。实验测得的反射次数为60，导致光程约为11 m，这与理论值10.95 m非常吻合。结合中心波数位于乙炔（CH）吸收线6521.2 cm处的近红外激光器，建立了一个CH传感器系统来验证基于三镜的气室的可行性。在数据采集（DAQ）卡的辅助下，开发了一个LabVIEW平台来生成激光器的驱动信号并从探测器的输出中采集二次谐波（2f）信号。通过阿伦方差分析，传感器系统在平均时间为0.5 s时的检测限（LoD）为4.36 ppm；当平均时间超过10 s时，LoD小于1 ppm。所提出的基于三镜的气室模型和设计可用于实现具有不同吸收光程的类似气室，用于基于红外吸收光谱的气体检测。
