非对称空间外差光谱技术研究

Study on Asymmetric Spatial Heterodyne Spectroscopy

传统空间外差光谱技术存在光谱分辨率、光谱范围与探测器象元数之间的制约关系。非对称空间外差光谱技术相比传统空间外差光谱技术主要区别在于增加单臂光栅到分束器的距离,能够在系统参数不变的情况下大大的增加光谱分辨率。首先阐述了非对称空间外差光谱技术的基本原理,并给出相应的系统参数计算公式推导结果,从理论上推导出单臂光栅偏置量增加和光谱分辨率增加之间的关系。偏置量作为非对称空间外差光谱技术的重要参数,受短双边象元数和光谱分辨率需求的制约。根据实验室现有实验平台参数,给出偏置量选择原则及结果。在元器件参数相同的情况下,分别计算了两种形式的理论光学性能参数,并且进行了仿真验证,得出非对称空问外差光谱仪与传统空间外差光谱仪光谱范围相同,但具有更高的光谱分辨率,并且分辨率提高与偏置量增加关系与理论计算相符。最后通过单色光扫描方法对非对称空间外差光谱仪实验室装置进行光谱范围和光谱分辨率的定标,定标结果与理论计算值吻合较好。

Restrictive relationship exists between spectral resolution ,spectral range and number of pixels of traditional Spatial Heterodyne Spectroscopy （SHS） .The main difference between Asymmetric Spatial Heterodyne Spectroscopy （ASHS） and SHS accelerates the space of one grating from the beamsplitter .It greatly increases spectral resolution while system parameters remain unchanged .First of all ,this paper elaborates the fundamentals of the ASHS ,the derived formulas of the system parameters and theoretical relationship between grating offset and the spectral resolution increases .As an important parameter of the ASHS , offset is restricted by the pixel number of short double side interferogram and the spectral resolution requirements .According to the experimental breadboard parameters of laboratory ,the selection principle and the results of the offset are presented .In the case of the same device parameters ,two types of theoretical performance parameters are calculated .The simulation is carried out .The results show that two of them have the same spectral range ,but the ASHS has a higher spectral resolution .The rela-tionship between resolution and offset increased consistent with theoretical calculation .Finally the ASHS breadboard is calibra-ted with the monochromatic light scanning method .The derived spectral range and resolution are in good agreement with the the-oretical value .