多色光大空间带宽积傅立叶变换透镜系统的设计

Design of multicolour optical Fourier transform systemwith large spacebandwidth product

本文根据傅立叶变换透镜系统的像差要求，通过研究衍射器件的色差特性和初级像差特点，提出了多色光大空间带宽积的傅立叶变换透镜的系统结构。此系统采用无光焦度的衍射器件校正傅立叶变换主镜的球差，使系统得到最大空间带宽积；还采用谐衍射器件的设计方法，使系统可对多种相干光实现光学傅立叶变换。相对传统傅立叶变换系统而言，此衍射系统结构简单，性能好，可望在光学信息处理方面得到广泛的应用。

In this paper the thirdorder monochromatic aberrations of general diffractive optical elements (DOE) and harmonic diffractive optical elements (HDOE) are analyzed based on the requirement of optical Fourier transfom system, and then a novel design of the multicolor Fourier transfom system is presented. In the system two techniques are adopted;one is using a nonfocal DOE to correct the spherical aberration and get the largest space bandwidth product; the other is adopting HDOE design method to realize the achromatic transform to multicolor light. Compared to the traditional optical Fourier transform lens system, this pure diffractive system can acquire better performance with much simpler structure, and so can be widely used in optical signal processing system.