Polarization of completely coherent random electromagnetic beams

It is shown that the spectral degree of polarization P((r) over right arrow, omega) of a fluctuating electromagnetic beam which is completely coherent throughout a domain D is necessarily the same at every point in D. It can take on any value in the range 0 \u3c = P \u3c = 1. In particular, the fully coherent beam can be completely polarized or completely unpolarized throughout D. (c) 2006 Optical Society of America