Logic Gates Through Three Core and Dual Core Nonlinear Directional Couplers Operating in Continuous Wave Mode

Abstract

We have studied and obtained logic gates through three-core nonlinear directional  couplers and dual-core nonlinear directional couplers operating in continuous wave  mode in which the laser signal has the same wavelength. In symmetrical three-core  nonlinear directional couplers with its identical cores in a planar arrangement was  studied using a control pulse applied to the first core. In dual core the structure was  the asymmetric two core switching process was held in symmetrical triangular fiber  couplers and three-core nonlinear directional couplers using the coupled mode of  the nonlinear Schrodinger equation. The logic gates, AND, OR and NXOR were  generated from the triangular three-core nonlinear directional couplers, while planar  three-core nonlinear directional couplers produced logic gates AND, NAND, OR  and XOR. For this two basic modes were considered. The first triangular structure  with three symmetrical core were considered from an equilateral triangle and used a  control signal applied to the first core. In the second model the symmetric cross  structure with three cores in a parallel equidistant arrangement. We have obtained  optical logic gates in a fiber coupler doped with erbium, leaded the resonant non  linearity to change the refractive index which helped to reduce the device switching  energy threshold.