红外光谱仪内部背景辐射在长波红外波段(8~12 μm)影响比较显著, 会严重降低光学系统的分辨率和信噪比。利用TracePro光学分析软件, 对基于交叉非对称Czerny-Turner(C-T)型平板波导红外光谱仪进行了背景辐射分析, 包括机械构件表面发射率以及光学元件表面温度对背景辐射的影响。引入了杂光系数作为评价指标, 根据仿真分析结果, 在高低温箱中, 对该红外光谱仪的背景辐射影响采取抑制措施并进行了实验测量, 实验结果证明: 采取背景辐射抑制措施后, C-T型平板波导光谱仪系统的杂光系数在常温下(298 K)能达到5%以下。

The internal background radiation of the infrared spectrometer has a significant effect which will seriously reduce the resolution and signal-to-noise ratio of the optical system in the long-wave infrared band(8-12 μm). In this paper, the TracePro optical analysis software was used to analyze the background radiation of the cross asymmetric Czerny-Turner (C-T) type planar waveguide infrared spectrometer, including the surface emissivity of the mechanical components and the influence of the surface temperature of the optical elements on the background radiation. The stray light coefficient was introduced as the evaluation indicator, and the actual measurement was carried out before and after the background radiation suppression of the spectrometer system in the high and low temperature box. The experimental results show that the stray light coefficient of the spectrometer system can reach less than 5% under the normal temperature (298 K) after the background radiation suppression measures are taken.