Modulational instabilities and Raman effect in birefringent fibers

The nonlinear optical response of silica glass fibres essentially comes from two distinct contributions: the nearly instantaneous dependence of the refractive index on field intensity, and the stimulated Raman effect. This presentation overviews several theoretical results concerning the non-linear dynamics of both continuous waves and short pulses in birefringent fibers. A purely electronic instantaneous response is considered first, and then the interplay between Raman and electronic nonlinearities in threshold determination for stimulated scattering is discussed in the undepleted pumps approximation. Studies of ultrashort pulse propagation in both normal and anomalous dispersion regimes are reported.