转镜透射式傅里叶光谱仪光程差的非线性分析

转镜透射式傅里叶光谱仪具有可靠性高、光谱分辨率高、测试速度快等优点，但在正常匀速转动扫描光程差的情况下，存在光程差的非线性问题。针对转镜透射式傅里叶光谱仪的光程差的扫描非线性问题进行了分析，提出了一种光程差非线性数学计算模型，建立了转镜光程差方程，并进行了MATLAB仿真分析。通过速度反馈电机控制转镜匀速旋转时，根据本文的非线性光程差方程可获得等光程差对应的时间非均匀关系，从而可实现时间的非均匀采样，并反演出准确光谱，而不必采用稳频氦氖激光器触发采样，可以节省成本和减小仪器的体积与重量。

Nonlinear Analysis of Optical Path Difference of Rotary Fourier Transform Spectrometer

Rotary Fourier transform spectrometers have many advantages such as high reliability, high spectral resolution and fast test speed etc. But when it scans optical path difference by uniform rotation, there is a nonlinear problem for the optical path. The nonlinear optical path difference scanning of a transmission Fourier spectrometer is analyzed. A mathematical model of nonlinear optical path difference is proposed. The optical path difference equation is established and the MATLAB simulation is carried out. When a rotating mirror is controlled to rotate at a constant speed by a speed feedback motor, the inhomogeneity of time can be obtained according to the established nonlinear equation. So the non-uniform sampling of time can be realized and accurate spectra can be obtained. Instead of using a stabilized He-Ne laser to trigger sampling, it can save cost and reduce the volume and weight of the spectrometer.