We discuss the degrees of polarization (DoP) of electromagnetic beams in time and frequency domains. The mean spectral DoP corresponds to the maximal temporal DoP when unitary transformations are applied in frequency domain. We demonstrate that random unitary transformations in frequency domain cannot increase the mean spectral DoP, implying that this quantity is a useful measure of the polarization order of light beams. This leads to a classification of time-domain polarization changes into reversible and irreversible processes.
© 2012 Optical Society of America
Coherence and Statistical Optics
Original Manuscript: June 13, 2012
Manuscript Accepted: July 20, 2012
Published: September 5, 2012
Philippe Réfrégier, Tero Setälä, and Ari T. Friberg, "Maximal polarization order of random optical beams: reversible and irreversible polarization variations," Opt. Lett. 37, 3750-3752 (2012)