傅里叶变换红外光谱仪中立方反射镜特性分析

在傅里叶变换红外光谱仪中,用立方反射镜作为动镜的光路系统比平面镜时的情形复杂。通过建立系统的数学模型分析光路,确定了干涉信号的数学表达式;从干涉图调制度的角度对系统在非理想状态下的运动误差容限以及安装误差容限进行了分析。结果表明,与动镜和定镜都采用角反射体的系统相比较,该系统动镜运动中其偏摆和顶点横移不会对干涉图产生影响;与动镜为平面镜的系统相比较,该系统不需要对动镜的动态校正就能满足调制度判据要求。

Analysis on corner cube retroreflector in FT-IR Spectrometer

The system of a Fourier transform infra-red(FT-IR) Spectrometer with a cube corner retroreflector(CCR) as moving mirror is analyzed,which is more complex than the situation of a mirror as moving mirror.Through establishing system mathematical model based on the FT-IR Spectrometer to analyze the tracks of light rays,the function of the interferogram is deduced.And the non-ideal state of moving error tolerance and installation error tolerance are studied theoretically by means of the modulation depth.Under these tolerances of errors the quality of interferogram and spectrogram would be little influenced.The result indicated that,compared to interferometer system of the dihedral corner mirrors or cube corner retroreflectors for both moving and fixed mirrors,the quality of interferogram would not be altered by the vibration and apex transverse dithering in the movement of CCR.The dynamic adaptive alignment to the CCR even isn't necessary in this system compared to the plane mirror(moving mirror) in the Michelson interferometer system.