Abstract
The intensity fluctuations of random electromagnetic beams propagating in the
atmosphere are studied. For such beams it is shown that when the atmospheric fluctuations are
weak then the scintillation index (the normalized variance of intensity fluctuations) of the
beam at any distance from the source depends not only on the state of coherence but also on
the degree of polarization of the beam in the source plane. In particular, we found that for
initially unpolarized beams the scintillation index generally takes on smaller values than that
for completely polarized beams. The presented analysis might be useful in the applications
(e.g. communications, laser radars) where atmospheric effects can be mitigated by adjusting
the coherence properties and the polarization properties of the source.
