Estudo dos interferômetros de Mach-Zehnder e de Sagnac de fibras ópticas tradicionais e de cristal fotônico na geração de portas lógicas ópticas

Abstract

In this paper, we investigated the operational characteristics of two optical devices, Mach- Zehnder interferometer (MZI) and Sagnac interferometer (NOLM). Numerical simulation studies of ultrashort pulse propagation and simulation are presented in a MZI composed of couplers and photonic crystal fiber, as well as in a NOLM made up of coupler and (conventional) traditional fiber. In the analysis of the devices we investigated the properties of the propagation of light pulses in the form of sólitons as well as the generation of logic gates and logic functions. Based on the nonlinear optics, ultrashort pulses were propagated, lasting 100 fs in the MZI and 10 ps in the NOLM. We first investigated a MZI configuration, where we performed a physical analysis of the device analyzing the transmission, extinction rate, crosstalk and factor compression by placing a nonlinearity profile on one of the arms of the MZI using On-Off switching where high order nonlinear effects (GVD, Self-Steepening, Raman, Coupling Dispersion) were considered in Schrödinger's Generalized Nonlinear Equation. We also investigated the Sagnac interferometer in traditional fiber without using high order effects and using PAM-ASK modulation, instead. The research was carried out through computational numerical simulations using the MatLab based software, using the fourth-order Runge Kutta method in the MZI and the Split-Step in the NOLM. We concluded that the proposed devices can be used to obtain the OR, AND and XOR logic gates. The best logical ports for each type of OR and XOR using FOMELG for the MZI were shown. Also, the logical gates of better quality AND, OR and XOR for the NOLM were presented according to the precision ratio (PR). The results provide support for applications in TDMA systems and fully optical networks.