Computing using pulse collisions in lattices of excitable microlasers

Coupled excitable microlasers have been shown theoretically to sustain saltatory propagation of solitonic-like excitations and hold good promise for fabrication of advanced and integrated photonic processing circuits. By studying a model for evanescently coupled excitable microlaser lattices with integrated saturable absorber, we investigate how pulse interaction can lead to non trivial responses. In particular, we show in a three-port system that depending on the system parameters and geometry, two counter-propagating pulses from two input ports can collide and exit or not in a third port, thus giving rise to the not-linearly separable XOR response function and to universal logic gates.