Multilevel Phase Structures for Array Generation

Array generators are optical systems which split a single beam from a laser source into a one- or two-dimensional array of beams. We are interested in the generation of spot arrays for illuminating two- dimensional arrays of optical logic devices in an optical digital computer. A variety of solutions to this problem has been offered, among them the use of computer generated diffraction gratings [1,2,3], holographically produced lenslet arrays [4] and phase contrast methods based on spatial filtering [5]. Binary Dammann gratings and arrays of lenslets have also been employed by Veldkamp et al. [6,7] for the inverse task of coherent coupling of the output beams of several laser diods.