All-optical diode effect of a nonlinear photonic crystal with a defect

An all-optical diode behavior that uses a nonlinear one-dimensional photonic crystal (NPC) with a defect Kerr medium is numerically simulated by the use of a nonlinear finite-difference time-domain (NFDTD) method. The numerical results show that for an incident pulse with appropriate intensity and temporal width, the transmittance can be several times greater in one direction of NPC than in the opposite direction at the pulse carrier frequency. This behaves like an all-optical diode and has promising applications in some areas such as optical isolation and all-optical processing. The ways to obtain low threshold of pulse field strength to realize an all-optical diode are also analyzed in detail.