All-Optical Modified Fredkin Gate

Conventional digital circuits lose energy because the bits of information are destroyed during the operation. Reversible circuits are currently on the top approaches to power minimization with its application in all-optical-based systems. Fredkin gate is a very common reversible logic gate. In this paper, a modification of the Fredkin gate is proposed. All-optical circuit of this modified Fredkin gate (MFG) is also designed using semiconductor optical amplifier on the Mach-Zehnder interferometer switch. A 16-Boolean logical operational circuit is also shown using this MFG. The main advantage of this scheme is that we can design a 15-Boolean logical function using a single MFG unit. Only one operation (nand) required two MFG units. Hence, complexity of the circuit can be reduced. Also, multivalued T-gate circuit using MFG is proposed.