Improper statistics of radiation from a randomly rotating source.

Abstract: Our earlier work [J. Opt. 19. (2017) 0905603] revealed that, in contrast to the four parameters of the traditional Stokes vector description of the statistics of the partially polarized light, the complete second-order statistics of the narrow-band polarized wave is characterized by thirteen parameters. Here we analyze the second-order statistics of the radiation from a randomly rotating source of the electromagnetic radiation, and show that it includes a covariance of the right and left circular polarizations that is not captured by the Stokes vector formalism. We illustrate this finding with simple examples of rotating quadrupoles and dipole pairs.