为了消除光学条纹对检测精度的影响, 基于光学条纹的映射特性, 提出了一种可有效补偿光路中平行介面造成的光学条纹的方法。在CO2检测系统中进行了理论分析和实验验证, 并展示了该方法的使用过程及补偿结果。结果表明, 即使在光学条纹漂移的情况下, 该方法仍可有效补偿光学条纹, 使测量信号与标准气体吸收信号的拟合相关度由0.8298提升至0.9934, 体积分数测量值标准差由1260×10-6降低至48.5×10-6。该方法极适合补偿检测器窗、气体池窗以及其它已集成于系统的光学元件造成的光学条纹, 在可调谐二极管激光器吸收光谱技术领域具有较大的应用价值。

In order to suppress effect of optical fringes on detection accuracy, based on the characteristics of optical fringes, a method was proposed to compensate the optical fringes produced by parallel surfaces. Theory analysis and experimental verification were performed in a carbon dioxide detection system. The process and compensation results were shown. The results show that even in the case of optical fringe drift, the method can effectively compensate the optical fringes. The fitting correlation between the measured gas absorption signal and the standard gas absorption signal is increased from 0.8298 to 0.9934. The standard deviation of the measurement value of volume fraction was reduced from 1260×10-6 to 48.5×10-6. The method is very suitable for compensating the optical fringes caused by detector windows, gas pool windows, and other optical elements integrated into the system. It has great application value in the field of tunable diode laser absorption spectroscopy.