Optical soliton solutions for Schrödinger type nonlinear evolution equations by the tan(Φ(ξ)/2)-expansion method

We analytically study the Schrödinger type nonlinear evolution equations by improved tan(Φ(ξ)/2)-expansion method. Explicit solutions are derived, which include optical bright solitons, dark solitons, singular solutions and singular triangular periodic solution. The exact particular solutions containing four types hyperbolic function solution, trigonometric function solution, exponential solution and rational solution. We obtained the further solutions comparing with other methods. Recently this method is developed for searching exact travelling wave solutions of nonlinear partial differential equations. It is shown that this method, with the help of symbolic computation, provide a straightforward and powerful mathematical tool for solving problems in nonlinear optic.