Image-contrast enhancement of wavefront coding systems by combining radially symmetrical phase and amplitude masks

The quartic phase mask is a radially symmetrical phase mask which is commonly used to analyze imaging performance and to apply in many practical applications. In this paper, we propose a simple, novel method to improve the image contrast for extending depth of field in wavefront coding system with radially symmetrical quartic phase mask. An amplitude mask, which improves image contrast in low spatial frequency region, is added on the wavefront coding system with quartic phase mask to obtain the remarkable improvement of imaging performance for extending depth of field. Some evaluation methods are used to show the effectiveness of imaging performance of the proposed method in comparison to previously phase mask. The results demonstrated that the proposed method yields better imaging property in extending depth of field