Asymmetric nonlinear coupling and its applications to logic functions

The phenomena of asymmetric nonlinear coupling are studied. The study is aimed at the application of nonlinear coupling to all-optical logic functions. Asymmetric nonlinear coupling signifies the nonlinear coupling between two single-mode waveguides of different nonlinearities. The simulation results of NOT, AND, OR, and XOR logic functions are presented. Also, the sensitivities of the results to the variations of various signal and coupler parameters are discussed. The simulation results included three types of input signals: CW waves, picosecond solitons, and femtosecond solitons. Because of the effect of group-velocity dispersion, the results of CW and pulsed signals are quite different. Because of the effects of shock effect and Raman response, the results of femtosecond soliton signals differ from those of picosecond soliton signals. When picosecond solitons are used as input signals, the outputs are still solitons.<
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