单光栅快照式光谱成像系统的设计

Design of single-grating snapshot spectral imaging system

相较于双光栅快照式光谱成像系统,单光栅结构的成像系统因其仅包含一个分光原件,所以在结构上更加简洁。本文搭建了一个单光栅快照式光谱成像系统,系统中采用数字微镜器件作为编码器件。首先,为了搭建成像系统实物,分析了该成像系统的数学模型;其次,对系统中透射光栅的偏移量进行计算;最后,使用交替方向乘子法对光谱成像系统采集到的图像进行多光谱重建。重建结果表明,2种波长的激光光斑图像可以准确地分开,且激光光谱位置较准确。

Compared with the dual-grating snapshot spectral imaging system, the imaging system with single-grating structure contains only one spectroscopic element, making the structure more compact. In this paper, a single grating snapshot spectral imaging system is built, in which a digital micro-mirror device is used as the encoding device. First, in order to build the physical imaging system, the mathematical model of the imaging system is analyzed. Then, the offset of the transmission grating in the system is calculated. Finally, multi-spectral reconstruction is conducted with images collected by the spectral imaging system via alternating direction multiplier method. The reconstruction results show that the laser spot images of the two wavelengths can be separated accurately, and the laser spectral position is more accurate.