Improving the image quality of optical systems with radially symmetrical phase mask

Abstract

An optical system with a radially symmetrical phase mask allows to extend the depth of field. However, the contrast of the optical system is still lower than that of the diffraction pattern of the traditional optical system. In this paper, we introduce a new method for image enhancement of optical systems with radially symmetric phase masks. The optical system with a traditional radial symmetric phase mask would result in a dot point spread function. The optical system with an improved symmetric phase mask results in a dark center point spread function. The two images that will be obtained correspond to the optical system with two phase masks. On the basis of these two images, a mathematical relationship is proposed in order to obtain good quality images. The simulation results have demonstrated the proposed method to improve the image quality of the optical system with the radial symmetrical phase mask.