传统的时间调制型傅里叶变换红外成像光谱仪的激光采样通过采用单个激光探测器探测激光干涉强度变化生成采样脉冲,其采样原理简单易实现。但该方法无法判断动镜移动的方向,也难以实现高频采样。对时间调制型傅里叶变换红外成像光谱仪的采样方案进行了对比分析,并针对快扫描采样方法提出了具体的实施方案。从原理和光路设计上介绍了一种适用于时间调制型傅里叶变换红外成像光谱仪的新的采样方法。该方法在传统引入参考激光的基础上,采用偏振的手段将参考激光分为具有固定相位差的两束光,并利用这两束光实现动镜移动方向的判断,以及干涉图样的4倍过采样。从原理上综合考虑了各个光学元件的偏振特性,并将该方法从基于正入射的平面镜推广到斜入射的中空角锥反射镜,扩大了该方法的适用范围,从原理上论证了该方法的可行性。

The laser sampling method of traditional time modulated Fourier transform imaging spectrometer is rely on the laser detector which detects the intensity of the laser interferometer. The principle of this method is easy to realize, but without the function to judge the movement direction of moving mirror or high frequency sample. In this paper, the sampling schemes of the time modulation Fourier transform infrared (FTIR) imaging spectrometer are compared and analyzed. Specific implementation solution is proposed for the rapid scan sampling method. And a sampling method which is suitable for the time modulation FTIR imaging spectrometer is introduced in principle and optical path design. This method divides the reference laser beam into two beams with fixed phase angle based on traditional reference laser method. And these two beams are utilized to estimate the moving direction of moving mirror and quadruple oversampling. On the basis of considering the various optical element polarization characteristics, this method is promoted from plane mirror to hollow retroreflectors that extend the application range of it. The feasibility of this method in principle has demonstrated in this paper.