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.
© 2002 Optical Society of America
Original Manuscript: January 10, 2002
Revised Manuscript: June 6, 2002
Published: October 10, 2002
Sherif S. Sherif and W. Thomas Cathey, "Reduced depth of field in incoherent hybrid imaging systems," Appl. Opt. 41, 6062-6074 (2002)