微型光谱仪平场全息凹面光栅的优化设计

Optimum design of flat-field holographic concave grating for micro-spectrometers

研究了应用于微型光谱仪的平场全息凹面光栅的设计方法,提出了全局优化和反向优化的设计思想.利用全局优化算法求解了用于设计平场全息凹面光栅的非线性方程组,可以通过调整某些像差项的优化权重,快速有效地完成设计;同时利用反向优化算法对设计的中间结果进行工作位置的微量调节,进一步提高了光栅的光学性能,并阐述了平场全息凹面光栅可以具有多工作位置的原因.以遗传算法为例实现了上述优化思想,并基于TCD1304AP线阵CCD探测器,设计了适用于工作波长为380-780 nm的微型光谱仪系统的平场全息凹面光栅.实际系统经测试得到了良好的成像效果,光谱分辨率可达0.8 nm（50μm狭缝）.

A design method with globe optimization and reverse optimization was presented to achieve a flat-field holographic concave grating used for micro-spectrometer system. Globe optimization algorithm was utilized to solve the nonlinear equation set of flat-field holographic concave grating, which helps the designer freely adjust the weights of specific aberrations during the design process and shorten the design time. Then, the idea of reverse optimization was raised to make little adjustment to the working parameters of intermediate results, which improves the optical performance of the grating. Base on this reverse optimization thought, the possibility of the gratings＇ multi-working configurations was enunciated. Genetic algorithm was adopted to realize the presented design thought. Based on a TCD1304AP linear CCD detector, a flat-field holographic concave grating used for micro-spectrometer with working wavelength range of 380-780 nm was designed. The results showed that the actual system＇s spectral resolution was about 0.8 nm when using 50 microns wide slit.