Finite-difference time-domain analysis of optical bistability with low threshold in one-dimensional nonlinear photonic crystal with Kerr medium

We present a nonlinear finite-difference time-domain (NFDTD) analysis of optical bistability (OB) in a one-dimensional nonlinear photonic crystal (1D-NPC) with Kerr medium under Debye relaxation. The properties of the defect modes in a symmetrical structure 1D-NPC and the way to obtain low threshold of OB is discussed in detail. The OB threshold depends on the optical thickness and refractive index of defect layer and the number of symmetrical layers. When the half-width of defect mode is small enough and frequency of incident light and linear refractive index are selected carefully, the low threshold OB is able to be obtained. By numerical simulation threshold ∼130 KW/m² is obtained, correspond refractive index change is only about 0.04.