  We report on trapped pulse generation in birefringent microstructured optical
fiber. Linearly polarized fs pulses are injected into the microstructured fiber
in anomalous dispersion regime. We observed experimentally that soliton pulse
polarized along the fast fiber axis partially transfers its energy to the
orthogonal polarization. The generated pulse is amplified through the
orthogonal Raman gain. The two polarization components are located at
group-velocity matched wavelengths. The experimental works are supported with
numerical simulations. The obtained results are important for the light sources
using self-frequency shifted solitons in applications demanding high
polarization purity.
