Analysis of pulse trapping characteristic in highly birefringent photonic crystal fiber

A theoretical investigation of the pulse trapping in a highly birefringent photonic crystal fiber was presented. The strict coupled nonlinear Schrödinger equations were numerically solved using a split-step Fourier algorithm. Different incidence conditions were discussed when the two pulses were polarized along the same polarization axes. The pump pulse in abnormal dispersion regime traped the signal pulse in the normal dispersion regime, and the signal pulse shifted to shorter wavelength with the pump pulse of the longer wavelength in order to keep the same group velocity. Different initial temporal separation between the pump pulse and the signal pulse leaded to different effect in the pulse trapping. As the input peak power of the pump pulse was increased, the red-shift of pump pulse was considerably enhanced with the simultaneous further blue-shift if the trapped pulse to satisfy the condition of group velocity matching. Pulse trapping was inconspicuous as the full width at half maximum of the pump pulse was increased. In order to realize pulse trapping, the wavelengths of the pump and signal pulses should be near the zero dispersion point and the discrepancy between two group velocities should be small.