基于定镜动态准直的傅里叶变换拉曼光谱仪

本文介绍了一种基于定镜动态准直的傅里叶变换拉曼光谱仪。光谱仪采用了迈克尔逊干涉仪将拉曼光信号调制成干涉信号,通过计算机对干涉信号做快速傅里叶变换(FFT)得到拉曼光谱。为了克服干涉仪中动镜和定镜两面平面反射镜之间在运动过程中产生倾斜和振动,导致拉曼光谱调制度和信噪比降低,设计中采用了通过控制三个磁力线圈的磁场力的方式动态调整定镜的姿态实现动态准直。采用单晶硅材料作为样品对仪器性能进行测试,实验结果表明,该拉曼光谱仪的分辨率达到2 cm-1,测试硫的光谱和三氧化二锑的光谱的信噪比优于100:1。该仪器的设计和研发为我国未来同类仪器的创新发展做出有益探索。

Fourier Transform Raman Spectrometer with Fixed Mirror Dynamic Collimation

A Fourier Transform Raman （FT-Raman） Spectrometer with dynamic collimation, which uses a fixed mirror, is described in this paper. The Raman signal can be modulated into interfered signal by the spectrometer using a Michaelson Interferometer, while the Raman spectrum can be obtained through computerized Fast Fourier Transform （FFT） calculation. The Modulate Ratio （MR） and Signal to Noise Ratio （SNR） may be decreased as a result of slanting and vibration between the adjustable mirror and the fixed mirror in a Michaelson Interferometer. A design to dynamically position the fixed mirror by changing the output fOrce of three magnetic coils was used to overcome the problem. Monocrystalline silicon was used as the sample to test the capability of the instrument. It was shown in the experiments that this FT-Raman spectrometer can yield a resolution of 2 cm-1, with the Signal to Noise Ratio （SNR） for sulfur and stibium trioxide at higher than 100：1. This instrument provides an excellent prototype for further research and development.