Free-space propagation of the spectral degree of cross-polarization of stochastic electromagnetic beams

Şahin S., Korotkova O., Zhang G., Pu J.

JOURNAL OF OPTICS A-PURE AND APPLIED OPTICS, vol.11, no.8, 2009 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 11 Issue: 8
  • Publication Date: 2009
  • Doi Number: 10.1088/1464-4258/11/8/085703
  • Journal Name: JOURNAL OF OPTICS A-PURE AND APPLIED OPTICS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED)
  • Keywords: propagation, random beams, electromagnetic beams, polarization, STOKES PARAMETERS, COHERENCE, STATE
  • TED University Affiliated: No

Abstract

Based on the unified theory of coherence and polarization and the extended Huygens-Fresnel integral the free-space evolution of the recently introduced spectral degree of cross-polarization of a stochastic electromagnetic beam is studied. Unlike the spectral degree of coherence, the degree of cross-polarization is unbounded and exhibits non-monotonic changes with growing propagation distance and growing radial distance from the center of the beam, at fixed transverse cross-sections. Our numerical results pertain to the electromagnetic Gaussian Schell-model beams. We derive expressions for the cross-spectral density matrix of the EGSM beam for arbitrary transverse and longitudinal positions. The results show that the behavior of the degree of cross-polarization on propagation is determined by all of the parameters of the source radiating the beam. At sufficiently large distances from the source, the degree of cross-polarization stabilizes for all points within the beam independently of their radial positions.