It has been known for some time that the degree of polarization of a light beam may change on propagation, even in free space. In this Letter we derive sufficiency conditions for the degree of polarization of a beam generated by a uniformly polarized stochastic, electromagnetic source of a wide class to be the same throughout the far zone and in the source plane.
© 2007 Optical Society of America
Original Manuscript: September 10, 2007
Manuscript Accepted: October 1, 2007
Published: November 20, 2007
Emil Wolf, "Polarization invariance in beam propagation," Opt. Lett. 32, 3400-3401 (2007)