基于谐波检测的调制光谱技术可以实现气体浓度的高灵敏检测,而最佳分析性能的实现依赖于系统调制参数 的优化。研究了基于谐波的红外激光调制光谱信号特征,分析了调制参数与谐波特性的对应关系,针对 典型的红外半导体激光光谱气体检测系统开展了实验研究与验证分析,获取了不同调制信号电压的谐 波信号特征,分析确定了系统最佳调制参数。

High sensitivity for gas detection can be achieved by modulation spectroscopy technology based on harmonic detection, and the best analytical performance depends on the system modulation parameters optimization. Harmonic signal characteristics of infrared laser modulation spectroscopy is studied, and the relationship between the modulation parameters and corresponding harmonic signals is analyzed. Experiments and validation analyses are carried out for the typical infrared diode laser spectroscopy gas detection system, the optimal modulation system parameter is determined through the experimental analysis of the harmonic signal characteristics for different modulation voltages.