Wavefront coding using coma aberration for dual field of view IR systems

Abstract

Wavefront coding (WFC) is a powerful hybrid optical-numerical technique for increasing the depth of focus of imaging systems. There is a low cost solution that uses decentred lenses inducing coma as an adjustable and removable phase element. This coding has been proven useful for IR systems. However these systems usually have several configurations with multiple fields of view. Unless the detector is uncooled, the f/number of the system is maintained for all configurations thus entrance pupil size changes for each one. As a result, the coding coma changes accordingly. This paper presents an approach to maintain the same amount of coma for dual field of view (DFOV) systems.