Polarization properties of partially coherent Gaussian Schell-model electromagnetic beams

The polarization properties of highly directional electromagnetic beams gen erated by planar sources of different states of spatial coherence are inves tigated. Cross-spectral density matrix based on modifications of Gaussian S chell-model beams is used. Azimuthally symmetric beams and dipolar beams ar e considered. The electromagnetic fields are assumed to be completely polar ized in the source plane. The variations of the degree of polarization in t he transverse directions and in the axial direction are examined. The depen dence of these variations on the degree of coherence of the source distribu tion is discussed. The depolarization effects of the fluctuations in the so urce distribution are found to be less severe for the dipolar beam as compa red to that for the azimuthally symmetric beam. (C) 2000 American Institute of Physics. [S0021- 8979(00)08009-9].