All-optical tunable photonic crystal NOR gate based on the nonlinear Kerr effect in a silicon nanocavity

A tunable NOR gate based on the Kerr effect in silicon-rod-based photonic crystals is presented. The proposed gate consists of two-dimensional photonic crystal add-drop filters with wavelength-selective reflector cavities, which are aligned in series with each other. The main feature of this structure is the enhancement of nonlinear phenomena caused by strong light localization in the photonic crystal nanocavities. Because of this feature, the designed NOR gate can control the amount of dropped probe signal light and change the gate output. The operation of the proposed gate is investigated numerically by using the finite-difference time domain method. The results reveal that the power levels of 0, 1, and uncertain states can be changed by appropriate adjustment of the probe signal frequency. (C) 2013 Optical Society of America