The Kundu equation is a general form of integrable system that is gauge-equivalent to the mixed nonlinear Schrödinger equation. It was proposed by Anjan Kundu as with arbitrary function and the subscripts denoting partial derivatives. Equation (1) is shown to be reducible for the choice of to an integrable class of mixed nonlinear Schrödinger equation with cubic–quintic nonlinearity, given in a representative form Here are independent parameters, while Equation , more specifically equation is known as the Kundu equation.