转镜式光谱仪光程差和非线性的研究

Studies of Optical Path Difference and Nonlinearity of High Speed Rotary Spectrometer

对转镜式高速干涉光谱仪的基本原理进行了介绍 ,给出了无晃动和有晃动两种情况下 ,轴上和轴外光线的光程差公式 ,并对结果进行了初步分析 ,发现晃动将使光程差大小发生变化 ,但不改变轴上光线零光程差的位置 光程差的非线性是转镜式干涉仪的天生缺陷 ,它和转镜的折射率、工作角等参量有关 ,使非线性最小可得出最佳折射率为 2 .9左右 ,从光程差误差的容限可以计算出对工作角的要求 ,折射率为最佳时 ,工作角可达 13.3° ,根据对非线性的分析结果 。

Basic theory of high-speed rotary Fourier Transform Spectrometer is introduced. Optical path differences (OPD) of on-axis rays and of space rays are deduced, and even when the rotating axis viberates. And these formulas are analyzed initially. Shaking changes OPD,but it maintains zero position of OPD. Nonlinearity of OPD relates to refractive index and rotating angle.The ideal refractive index,about 2.9,can induce minimal nonlinearity.The maximal rotating effective angle reaches 13.3 when the ideal refractive rotator is used. The principles of choosing refractive index of rotor and maximal effective rotating angle are given by the above results.