Noncoherent-optics systems are linear in irradiance, which is a nonnegative, real quantity; bipolar and complex data must be indirectly represented. We compare spatial representation methods and evaluate their relative merits.
I. Glaser, I. Glaser,
"Representing Bipolar And Complex Imagery In Noncoherent Optics Image Processing Systems: Comparison Of Approaches," Optical Engineering 20(4), 204568 (1 August 1981). https://doi.org/10.1117/12.7972763