同步辐射中FT-IR谱仪入射光束角度偏移对光谱测量的影响

The influence of incident beam's angle offset of Fourier transform infrared spectrometer on the spectrum measurement explored with synchrotron radiation

干涉仪的入射光束存在角度偏移将会在采集到的数据中引入噪声。本文以两个谱分布函数(高斯函数,矩形函数)为对象,比较正入射和存在入射角偏移情况下通过傅立叶逆变换所算得的谱分布的差别,来分析干涉仪入射光束角度偏移的影响,得到由于角度偏移量θ的存在会导致所算得的谱分布整体发生偏移。并进一步分析红外光束线中影响光谱仪入射光束角度的因素。通过对光谱仪入射角影响因素的分析,结合所得到的入射角偏移量θ的影响,按照束线设计的性能要求给出光路上各光学元件安装精度和光源位置抖动的要求。

Effects of the incident angle offset on FT-IR spectra are investigated in this paper.The simulated FT-IR spectra are obtained by Fourier inverse transform.The results show that this frequency shift varies with the angle offset of the incident beam in FT-IR.As an example,the factors that affect the angle of incident IR light at SSRF are analyzed.According to performance specifications of the IR beamline,requirements of the optical component installation precision and position drift of the light source are given.