title: Reduced depth of field in incoherent hybrid imaging systems.
abstract: A hybrid imaging system combines a modified optical imaging module and a digital postprocessing step. We define what to our knowledge is a new metric to quantify the blurring of a defocused image that is more suitable than the defocus parameter for describing defocused hybrid imaging systems. We use this metric to design a pupil phase grating to reduce the depth of field, thereby increasing the axial resolution, of an incoherent hybrid imaging system using quasi-monochromatic illumination. By introducing this grating at the exit pupil and digitally processing the output of the detector, we reduce the depth of field by more than a factor of 2. Finally, we examine the effect of using a CCD optical detector, instead of an ideal optical detector, on the reduction of the depth of field.
authors.affiliation: Imaging Systems Laboratory, University of Colorado, Boulder, 80309, USA. Sherif@colorado.edu
authors.forename: Sherif S
authors.initials: SS
authors.lastname: Sherif
authors.forename: W Thomas
authors.initials: WT
authors.lastname: Cathey