All-optical and combinational optoelectronic logic gates using chaotic synchronization of coupling-feedback semiconductor lasers and amplitude modulation

Abstract

Chaotic synchronization of coupling-feedback semiconductor laser diodes is theoretically studied for optical logic gate applications. The constructions of the fundamental all-optical XNOR, NOR, NOT gates and combinatorial optoelectronic logic gate and their physical models are presented. The computational principles and methods are defined for these logic gates. Two laser diodes commonly driven by a monochromatic light beam become chaos. Chaotic synchronization between the two lasers is achieved by coupling-feedback. Based on the system and an external optical modulation method, the all-optical logic gates are performed for digit computation via the amplitude modulator modulating the coupling light to synchronize or un-synchronize two chaotic states. And the combinational optoelectronic logic gate is implemented for digit computation by modulating the amplitude of coupling light and the current to synchronize or un-synchronize two chaotic states. Lastly, the effect of resynchronization and reunsynchronization on logic output was analyzed numerically, in detail. Numerical simulations show the validity and feasibility of the methods.