基于RGB三波段的消色差衍射透镜设计与分析

Design and Analysis of Diffractive Achromats Based on RGB Three-Band

针对传统衍射透镜工作在宽波段时色散严重、像质不佳的问题,提出一种基于RGB三波段的单片式分区消色差衍射透镜的设计方法。采用标量衍射理论对等宽度和等面积两种分区方式进行仿真分析,并在点扩展函数和衍射效率等方面与传统衍射透镜进行对比和分析。分析结果显示,分区消色差衍射透镜在RGB三波段工作时,三个波长衍射效率的标准偏差由传统衍射透镜的0.6607下降到0.1519和0.0592,同时保持良好的成像效果。最后,考虑到实际加工情况,分别仿真了不同分区方式下微结构量化为八台阶所对应的光学性能参数。结果表明,所设计方法可以使得工作在RGB三波段的衍射透镜具备良好的消色差性能,具有一定的实用性和普适性。

When traditional diffraction lenses work in a wide band,the results have severe dispersion and poor image quality.Thus,an optimized design method for a partition diffractive achromat based on RGB three-band is proposed.We use scalar diffraction theory to simulate and analyze the image of equal width diffractive achromats and equal area diffractive achromats which compare with traditional diffraction lenses in point spread function and diffraction efficiency.The analysis results show that the proposed partition diffractive achromat can reduce the standard deviation of the three-wavelength diffraction efficiency from 0.6607 of the traditional diffractive lens to 0.1519 and 0.0592 when working in the RGB three-band while maintaining imaging effects well.Finally,considering the actual processing conditions,the optical performance parameters corresponding to the microstructure quantization into eight steps under different partitioning methods were simulated.The results show that the proposed design method can make the diffraction lens achieve a good achromatic effect in the RGB three-band.Moreover,the proposed method has practicability and universal applicability.