Comprehensive performance analysis of popular odd-symmetric phase masks used for wave-front coded imaging system

Abstract

Wave-front coding was proposed in 1995 and is a powerful system-level technique used to extend the depth of field (DOF) of incoherent imaging system. The key to wave-front coding lies in the design of suitable phase masks which make the imaging system insensitive to defocus and defocus-related aberrations. Among all phase masks used for wave-front coding, odd-symmetric types are dominant and can provide larger extended DOF. With the acceptable degradation of MTF (Modulation Transfer Function) taken as a criterion, optimization procedure is used to obtain the optimum parameters for popular odd-symmetric phase masks and then a comprehensive analysis is carried out by considering four factors: DOF extension capability, sensitiveness to elementary aberrations, PSF (Point Spread Function) shifting effect and restorability of intermediate blurred images. To the best of our knowledge, the comprehensive analysis on performance of popular odd-symmetric phase masks, as done in this manuscript, has not been made before. So, the work reported here could be considered as a complementary part to the field of wave-front coding.