相关光谱式气体检测系统的光学仿真及优化

The Optical Simulation and Optimization of Gas Detection System Based on Correlation Spectroscopy Technology

依据相关光谱式红外气体传感器检测原理,以系统中红外光与气体反应的气室为研究对象,利用光学设计专用软件Tracepro对理想红外朗伯光源在不同反射镜类型下光源的最佳位置进行了仿真分析;通过建立光路传输系统的数学模型,对气室不同结构尺寸下的光功率输出、以及气室内壁反射率对传感系统性能的影响进行了仿真与优化.在理论模型的基础上,根据仿真结果,确定了最佳气室模型的参数组合.实验结果表明,通过对气室中红外光源的位置、反射镜类型、气室长度等部分进行适当的优化修改后,可使探测器接收信号幅度得到明显提高,将有利于后级电路的信号放大、数模转换等处理过程,从而提高气体浓度检测的灵敏度和精度.

According to the detection principle of infrared gas sensor based on correlation spectroscopy technology, with the chamber of the system in which the infrared light reacted to the gas as the research object, the best locations of the ideal infrared Lambert light sources were simulated and analyzed in different type reflectors using the optical design professional software Tracepro in this paper. By establishing the mathematical model of the optical trans- mission system, the optical power output of the chamber under different structural dimensions and the effect on the performance of sensing system of the chamber wall reflectivity were sim- ulated and optimized. Based on the theoretical model, the optimal parameter combination of the chamber model was determined according to the simulation results. The experimental results show that the signal amplitude of the detector can be significantly increased through proper optimization and modifications in the position of infrared light source, reflector type, length and other parts of the chamber, which will be conducive to the subsequent process of signal amplification, digital-analog conversion, etc., and this can thereby enhance the sensi- tivity and accuracy of the system in gas detection.