Nonlinearity effect on dual photonic crystal fiber coupler for generating fully optical logic gates

In this work, we present a numerical investigation of the asymmetric double nonlinear coupling of photonic crystal fibers in an on-off switch to obtain fully optical logic gates. Ultra-short pulses (100 fs) are propagated through the device in three distinct excitation power regimes, power below critical (P-o = 72 kW, where P-o represents the excitation power of the device), critical power (P-c = 103.5 kW, where P-c represents critical Power for which the power switching is 50% for both guides. There are cases where P-o is above the critical value, there are cases that is below), and power above critical (P-o = 110 kW). The pulse switching characteristics are analyzed as a function of the input power and the nonlinearity profile (beta-beta) inserted in one of the component guides. The nonlinearity profiles follow the regimes: constant, increasing and decreasing, and high order effects, such as third-order dispersion, intrapulse Raman scattering and self-steepening are included in the generalized Schrodinger nonlinear equation governs the pulse propagation dynamics. The results show that the proposed device can be used to obtain AND, OR, and NOT logic gate. Numerical studies were done from the coupled-coupled equations solved using the fourth-order Runge-Kutta method, using MATLAB as a programming tool for solving equations. The implementation of fully optical logic gates tends to revolutionize new digital systems in the field of data storage, such as optical memory, "replacement" of electronic circuits among other applications. Optical systems have a great advantage as they are free from electromagnetic interference and have high rates of data transmission.