Nonlinear all-optical digital amplification of light pulses based on coupled photonic crystal guiding nanostructures

All-optical amplification of the light pulse in a weakly coupled nonlinear photonic crystal waveguides (PCWs) is proposed. We consider pillar-type PCWs, which consist of the periodically distributed circular rods made from a Kerr-type dielectric material. The operating frequency is properly chosen to be located at the edge of the dispersion diagram of the modes. In case of nonlinear medium when the amplitude of the injected signal is above some threshold value, solitons are formed and they are propagating inside the coupled nonlinear PCWs. Near field distributions of the light pulse and the output powers of the registered signals are studied in a detail. A good agreement between the numerical and theoretical studies is observed.