Invariant parameters for characterizing nonuniformly partially polarized beams

In terms of the so-called Wigner-Stokes formalism, within the framework of the second-order irradiance moments of the field, new overall parameters are introduced to characterize the polarization structure of nonuniformly partially polarized beams. These parameters are shown to be invariant upon rotation of the transverse Cartesian coordinate axes, which define the electric field components. Moreover, such parameters are also invariant under propagation through general rotationally symmetric ABCD optical systems.