Experimental realisation of parallel optical logic gates and combinational logic using multiple beam interference

In this paper, we report the experimental realisation of parallel optical logic gates and some combinational logic using multiple beam interference in three cascaded Michelson type interferometers. Considering light intensity at different points of 2-D interference pattern of four input laser beams as output, (i) two input AND, OR, NAND, NOR, XOR, XNOR optical logic gates in parallel, (ii) three input AND and NAND optical logic gates in parallel, and (iii) four input AND logic gate as well as some combinational logic in parallel were realised. By controlling the four input laser beams electro-optically or all-optically using nonlinear optical materials having large nonlinearity and fast response time, ultrafast photonic information processing can be performed utilizing present scheme due to parallel operation of large number of logic gates.