Based on zero-curvature equation, a series of new four-component nonlinear Schrödinger-type equations related to a [Formula: see text] matrix problem are proposed by using the polynomial expansion of the spectral parameter. As two special reductions, a generalized coupled nonlinear Schrödinger equation and a generalized coupled derivative nonlinear Schrödinger equation are obtained. And then, the infinite conservation laws for each of these four-component nonlinear Schrödinger-type equations are constructed with the aid of the Riccati-type equations.
Microscopic conservation laws for the derivative Nonlinear Schrödinger equation
