Abstract
We consider the evolution of attosecond light pulses in an optical fiber medium wherein the pulse propagation is governed by a fifth-order nonlinear SchrOdinger equation with constant coefficients. In addition to the cubic nonlinearity and group velocity dispersion terms, the model incorporates the third-, fourth-, and fifth-order dispersion and nonlinear terms related to them. Using a complex envelope function ansatz, we find the analytical solitary wave solutions of the model under some parametric conditions. The reported solutions describe bright and dark solitary waves that propagate on a continuous wave background in the presence of higher-order effects. The constraint relations among the optical material parameters for the existence of these localized structures are also discussed.