基于双边倾斜傅里叶干涉具的激光光谱探测技术研究

为了在不改变静态傅里叶干涉具尺寸的基础上提高光谱分辨率，设计了双边倾斜傅里叶干涉具及等光程条纹展宽的方法。通过计算分析双边倾斜傅里叶干涉具空间产生光程差与传统干涉具光程差的关系，得到在整个干涉具尺寸不变的条件下，光谱分辨率提高到9.1 cm-1，比同尺寸静态傅里叶干涉具提高了近8倍，并且不会因干涉条纹混叠而造成无法采集。采用BK7材料加工制成双边倾斜傅里叶干涉具，用6种不同波长的激光照射分析干涉条纹，实验结果显示干涉条纹会因反射位置增大而导致探测波长较长的激光时中心波长偏大，根据其满足线性变化的规律，拟合可知每1nm的激光波长变化造成0.021 1 nm的增大误差，经过标定后平均误差与传统干涉具接近，同时可以有效地提高静态干涉系统的光谱分辨率。

Research on Laser Spectrum Detecting Technology Based on the Bilateral-Wedges Fourier Interferometer

To increase the spectrum resolution without changing the size of static Fourier interferometer, the bilateral-wedges Fourier transform interferometer was designed and the methods of stretching interference fringes in the same optical path difference were proposed. Through analyzing the optical path difference function between the bilateral-wedges Fourier transform interferometer and static Fourier transform interferometer, the spectrum resolution was enhanced to 9.1 cm-1 with the same size, and the enhancement was nearly 8 times. It will not bring about being unable to collect the interference fringes due to fringe aliasing. In the experiments, the bilateral-wedges Fourier transform interferometer was made by the BK7, using laser with six different wavelengths to show analysis of interference fringes. The experimental result demonstrated the interference fringes to be longer than normal with the augmentation of the reflection position. Of course, the kind of this error can be calibrated, because it is linear augmentation by wavelength. According to the calculation, it is known that each 1nm of the laser wavelength change causes 0.021 1 nm increase in the error. After the spectrum calibration, the system can detect the correct spectrum data, raising the spectrum resolution with the same size.