Research Of All-Optical Logic Gates Based On Fwm Effect In High Nonlinear Fiber

All-optical logic gate is a key component in all-optical network, and can be applied to signal regeneration and optical packet routing and so on in network nodes. Its performance directly determines whether the all-optical network(AON) can work smoothly. Therefore, improving the response speed of optical logic gates has been a popular research topic in recent years.Optical logic gates based on four-wave mixing(FWM) in high nonlinear fiber(HNLF) own quick response, high efficiency, low loss, and transparent support to amplitudes and phases of the signals. So this is an attractively method to realize all-optical logic gates.This paper mainly studies the high speed all-optical logic AND gate and XOR gate based on FWM effect in HNLF. The main works of this paper are as follows:1. Based on basic theory of FWM effect in optical fiber, the influences of the phase mismatch factor, wavelength and the wavelength difference between signal and probe wave on FWM efficiency have been discussed. To achieve high efficiency FWM in fiber, the basic parameters also have been optimized.2. Based on FWM effect in HNLF, all-optical logic AND gate is realized which its processing speed can reach100Gbit/s. The complex amplitude of idler wave, which generated in the four-wave mixing process of fiber, is proportional to the product of complex amplitudes of signal light and probe light. Based on this theory, all-optical logic AND gate can be achieved. In addition, the coupled nonlinear Schrodinger equation including FWM effect is solved by the finite difference method. Numerical results are consistent with the conclusion of theoretical analysis, which proves the feasibility of achieving all-optical AND gate using FWM effect. Besides, the parameters of the system to achieve all-optical AND gate are effectively optimized.3. All-optical logic XOR gate is realized based on FWM effect in HNLF. A100Gbit/s all-optical logic XOR gate for carrier-suppressed return-to-zero differential phase-shift keying (CSRZ-DPSK) has been simulated. All-optical logic XOR gate is realized, according to the XOR relationship of phases of the idler and input optical signals in the non-degenerate FWM process. Further, MATLAB program is written based on the coupled Schrodinger equation including FWM effect. On the basis of the simulation results, the effects of different kinds of factors on all-optical logic XOR gate have been analyzed, and the optimized parameters of the realization of the high speed all-optical logic XOR gate have been given.All-optical logic AND and XOR gate, based on the FWM in HNLF, are deeply studied in this paper. The parameters’ effect on optical logic gate’s performances are discussed, and the parameters are optimized as well. This provides a theoretical reference for high speed optical logic gate’s realization.