All-optical method of developing half and full subtractors by the use of phase encoding principle

In this paper the authors proposed all-optical half subtractor and full subtractor using phase encoding technique. The processing part of the proposed model is consists of numbers of optical coherent mixers and mirrors. Optical switches are used only in the encoding of inputs, but no such switches are used in the processing part. So real time operation based on this proposed encoding may be achieved. The output of the system always carries same intensity and therefore it is suitable for using in a combinational and sequential logic system.