Coded Apertures And Detectors For Optical Differentiation

The general properties which an optical system must possess to display amplitude or phase contrast of both differential and non differential form are derived. These results are applied to various forms of scanning image processing systems and it is found that by suitable choice of lens or detector distribution that the desired contrast mode may be obtained. The coherent confocal system is particularly suited to the methods of coherent processing with the additional advantage of possessing twice the spatial frequency bandwidth of conventional systems.