Polarization-induced coherence changes and conditions for the invariance of the spectral degree of coherence produced by an electromagnetic wave scattering on a collection of particles

摘要

The scattered field generated by an arbitrary polarized electromagnetic plane wave incident on a collection of particles is studied. First, formulas for the spectral density and spectral degree of coherence of the scattered field are derived. Then, the polarization-induced coherence changes of a spatially coherent electromagnetic light wave scattered from a collection of particles are explored, and the results show that the spectral coherence of the scattered field consists of three independent parts. One depends on the polarization properties of the incident wave; another depends on the scattering potential of the particle; the third depends on the generalized pair-structure factor of the particle system. Lastly, the conditions for the invariant spectral degree of coherence of an arbitrary polarized wave scattered from a collection of particles are discussed. Apart from the geometrical factor, the modulus of the generalized pair-structure factor of the particle system and the modulus of the correlation function of the scattering potential can be factorized.