Depth of Field Control in Incoherent Hybrid Imaging Systems

Abstract

A hybrid imaging system combines a modified optical imaging system and a digital post-processing step.We define a new metric to quantify the blurring of a defocused image that is more suitable than the defocus parameter for hybrid imaging systems.

We describe a spatial-domain method to design a pupil phase plate to extend the depth of field of an incoherent hybrid imaging system with a rectangular aperture. We use this method to obtain a pupil phase plate to extend the depth of field, which we refer to as the logarithmic phase plate. By introducing a logarithmic phase plate at the exit pupil and digitally processing the output of the detector, the depth of field is extended by an order of magnitude more than the Hopkins defocus criterion [1]. We compare the performance of the logarithmic phase plate with other extended-depth-of-field phase plates in extending the depth of field of incoherent hybrid imaging systems with rectangular and circular apertures.