We report on trapped pulse generation in birefringent photonic crystal fiber. Linearly polarized ultrashort pulses are injected into the fiber in an anomalous dispersion regime. We observed experimentally that a 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 in agreement with numerical simulations. The obtained results are important for applications of the light sources using self-frequency shifted solitons that demand high polarization purity.