Optical computing and optical data processing are strongly believed to be the most feasible technology that can provide way out of the extreme limitations imposed on the speed and complexity of present days computation and communication by conventional electronics. Optics provides higher bandwidth than electronics, which enables more information to be carried simultaneously and data to be processed in parallel with impressive increase in speed by several orders of magnitude over that of the electronic signals. If the parallelism of optics be associated with fast switching speed of optical...