摆镜扫描傅里叶变换光谱仪光程差计算

Calculation on optical path difference of oscillating Fourier transform spectrometer

摆镜扫描傅里叶变换光谱仪利用摆动扫描方式产生光程差,减小了因动镜倾斜带来的误差影响。从摆扫干涉光谱技术原理出发,对摆镜扫描傅里叶变换光谱仪的光程差进行理论分析,给出了光程差计算表达式,实验结果表明:该光谱仪光程差近似正比于摆动角度。分析了轴外光线因不同入射角所产生的附加光程差,为傅里叶变换光谱仪的指标确定和优化设计提供了理论依据。

The optical path difference is an important character in Fourier transform spectrometer,and the optical path difference is produced by means of moving mirrors in spectrometer.Based on the scanning interference spectroscopy principle,the optical path difference of the spectrometer was analyzed theoretically,and its calculation expression was given.Results show that the optical path difference is approximately proportional to the swing angle.Additional,the optical path differences between beams of light associated with different incident angles were also pointed out.The studies pave the way for optimization design of Fourier transform spectrometer.