Computational imaging through chromatic aberration corrected diffractive optical element

Abstract

Conventional imaging systems for correction of geometric and chromatic aberrations often use two dozen individual optical elements. In recent years, researchers have introduced computational imaging to this situation. By relaxing constraints on the front-end optical system and using algorithms for restoration on the image side it can achieve high-quality imaging. In this paper,we used single DOE (diffractive optical element) and CIT (computational imaging technology) to achieve clear imaging in the visible-band from 400nm to 700nm. In optical design, PSF (point spread function) with wavelength consistency are obtained by coding the structure height of the DOE. In image recovery, the characteristics of a large diameter of PSF proposes a multi-scale deconvolution restoration algorithm. The deconvolution smooth noise is used to the low scale, and then recover the original size to achieve image restoration. The simulation shows that the frequency of the traditional phase Fresnel diffraction lens in this band when the MTF at 0.1 is only 2.58p/mm, while this method can achieve 110p/mm under the same condition. The results prove that DOE based on computational imaging can achieve visible-band achromatic and clear imaging effects maintaining a thin and light physical structure.