AN ANALYTICAL TREATMENT OF THE EFFECT OF AXIAL INHOMOGENEITY ON FEMTOSECOND SOLITARY WAVES NEAR THE ZERO DISPERSION POINT

A perturbed nonlinear Schrodinger equation, valid for femtosecond puls e propagation in axially inhomogeneous optical fibers near the zero di spersion point, is considered, It is found that for a weak axial nonun iformity, and under certain conditions, this equation can be treated a nalytically. Exact bright and dark solitary wave solutions are derived and their behavior in the presence of the inhomogeneity is analyzed, The nonuniformity induced time shift of the solitary waves is also obt ained, The potential use of this parameter as a diagnostic tool for es timating characteristic parameters of the axial variations is discusse d and its range of values is investigated.