Dark Solitary Wave Solutions for the Fourth-Order Nonlinear Schrödinger Equation with Cubic-quintic Non-Kerr Terms

Through adopting an ansätz solution, we study dark solitary wave solutions of the fourth-order nonlinear Schrödinger equation with cubic-quintic non-Kerr terms, especially under certain parametric conditions whose amplitudes do not approach to zero when the time approaches to infinity. In this context, we take into account both Fourth-order dispersion and higher nonlinear effect.