Two-pupil synthesis of optical transfer functions.

Incoherent optical spatial filtering systems have a number of advantages over their coherent counterparts; however, they are limited in their conventional form to operating with nonnegative-real input, output, and pointspread distributions. Most serious is the limitation to nonnegative-real impulse responses. A broad class of hybrid methods is investigated that employs two pupils in the synthesis of bipolar-real impulse responses. The mathematical structure of these syntheses is presented along with limitations in the presence of various constraints. Minimization of image plane bias is considered. Methods for implementation are described and categorized.