Polarization dependence of femtosecond soliton–soliton interactions in dispersion-shifted fiber

The polarization dependence of femtosecond soliton–soliton interaction in a dispersion-shifted fiber has been investigated in detail theoretically and experimentally. For 400-fs soliton pulses the input pulse separation at which the soliton–soliton interaction occurs is 1.6 ps for orthogonally polarized solitons as opposed to 2.3 ps when the polarizations are parallel. Similar to that in the parallel condition, the soliton self-frequency shift in the orthogonal case is accelerated through soliton–soliton interaction. However, the magnitude of the soliton self-frequency shift is reduced to one third of that in the parallel condition.