EFFECT OF A SUBWAVELENGTH LAYER ON ALL OPTICAL-DIODE ACTION IN 1D PHOTONIC CRYSTAL

In this paper, the effect of a subwavelength layer thickness with positive-refractive index material on all-optical diode action in a one-dimensional photonic crystal structure is investigated. An asymmetric multilayer stack composed of Kerr-type nonlinear and linear dielectric media and a subwavelength layer is considered. Behaviour of the linear transmission defect mode and nonlinear optical bistabilities for normal incidence of wave to 1D photonic crystal structure from left and right sides are studied. It is demonstrated that, with increasing of the subwavelength layer thickness, the linear defect mode shifts to the lower frequencies. Also, the left to right one-way transmission property of the structure is changed for right to left transmission at some subwavelength layer thicknesses. The changes of lower and higher bistability intensities thresholds and difference between left to right and right to left nonlinear transmissions versus subwavelength layer thickness are graphically illustrated. The photonic crystal all-optical diode is one of the important integrated devices, which has potential applications in the field of optical computing, optical interconnection systems and integrated photonic circuits.