Chaotic synchronization to realize the optical nor logic gate via mutual coupling semiconductor lasers

Theoretical construction of the fundamental NOR gate using two injection laser diodes due to themselves mutual coupling is reported. Synchronization between two injection laser diodes in chaos is achieved via coupling mutually the two lasers while the optical logic gate is finally implemented by appropriately synchronizing or un-synchronizing the two chaotic states. Two kinds of fundamental NOR gates using single-signal modulation and dual-signal modulation of the currents are presented. Numerical results illustrate that the two NOR gates would operate NOR computing.