title: A three-dimensional degree of polarization based on Rayleigh scattering.
abstract: A measure of the degree of polarization for the three-dimensional polarization matrix (coherence matrix) of an electromagnetic field is proposed, based on Rayleigh scattering. The degree of polarization at a point is defined as an average, over all scattering directions, of an imagined dipole scattering of the three-dimensional state of polarization. This gives a well-defined purity measure, which, unlike other proposed measures of the three-dimensional degree of polarization, is not a unitary invariant of the matrix. This is demonstrated and discussed for several examples, including a partially polarized transverse beam.
authors.affiliation: School of Mathematics, University of Southampton, UK. mark.dennis@soton.ac.uk
authors.forename: Mark R
authors.initials: MR
authors.lastname: Dennis