All-optical XOR and OR by Mach-Zehnder Interferometer engineered photonic crystal fibers

作者：Sales J C; Filho A F G F; Ferreira A C^*; Sousa J R R; Sobrinho C S; Menezes J W M; Guimaraes G F; Sombra A S B

来源：Optics and Laser Technology, 2017, 94: 128-137.

DOI：10.1016/j.optlastec.2017.03.012

• Mach-Zehnder Interferometer (MZI)
• On-off keying (OOK)
• All-optical logic gate
• Photonic crystal fiber
• All-optical signal processing
• Optical waveguide
• FOMELG

In this paper, we present a numerical investigation of all-optical logic gates based on a Mach-Zehnder Interferometer (MZI) configuration of micro structured fibers, also known as photonic crystal fibers (PCF) under optical OOK (on-off keying). We determine several relevant quantities to characterize the system performance, such as transmission and extinction ratio as a function of the nonlinearity profile (beta) added to one of the Mach-Zehnder Interferometer (MZI) arms. High-order effects such as third order dispersion, intrapulse Raman scattering and self-steepening were included in the generalized nonlinear Schrodinger equation describing the pulse propagation. For this study, we used an optical pulse with a shape of hyperbolic secant of 100 fs (femtosecond). A pumped laser with three power values was simulated. With critical power Pc = 103.5 kW (P = Pc), below the critical power P = 90 kW (P < Pc) and above the critical power P = 110 kW (P > Pc). We added a nonlinearity profile in one of the Mach-Zehnder Interferometer (MZI) arms. Nonlinearity profiles were expressed in terms of the parameter beta. We studied three different profiles: constant, increasing and decreasing. Our results show that the proposed device can be used to obtain all-optical OR and XOR logic gates as well as logic functions A and A.(B) over bar. The OR logic gate was the one which achieved the greatest FOMELG (Figure of Merit of Logic Gates) when using increasing profile with critical power (P-0 = 103.5 kW) for beta = 1.05 and FOMELG = 15.68 dB. The XOR logic gate presented the greatest FOMELG = 7.75 dB when using the decreasing profile with power below the critical (P-0 = 90 kW) for beta = 1.44. These results provide support for applications in all optical networks.

• 出版日期2017-9-1