All-optical regeneration based on highly nonlinear photonic crystal fiber

An all-optical regeneration based on self-phase modulation in a highly nonlinear photonic crystal fiber is proposed. The dispersion and nonlinearity properties of a series of photonic crystal fibers are analyzed, and the results show that the nonlinearity coefficient is closely related to the structure of the fiber. In this paper, the nonlinearity coefficient is increased by reducing the effective mode area, and a highly nonlinear photonic crystal fiber with a large air-filling fraction is used as nonlinearity medium in optical regeneration. The numerical results show that good optical regeneration results can be obtained by using a relatively short fiber length due to the high nonlinearity of the fiber. The input peak power launched into the photonic crystal fiber and the parameters of the filter have much influence on optical regeneration. To achieve good optical regeneration, those parameters need to meet certain requirements. Furthermore, the transfer characteristic of the regenerator is also discussed. By adjusting the input peak power and filter parameters, the regenerator can deal with input pulses of different pulse widths. © 2008 Higher Education Press and Springer-Verlag GmbH.