Array generation with multilevel phase gratings

Abstract

The efficiency of phase gratings used for array illuminators can be improved by increasing the number of phase levels in computer-generated diffraction gratings. This is of interest to provide power to two-dimensional arrays of optical logic devices that are used for optical computing purposes. The theory and fabrication techniques are described, and the experimental performance of a four-level grating that produces a 5 × 5 array is presented.