Polarization properties of fluctuations of the field created by randomly located dipoles

Abstract

The vector properties of the strength of a field created by an ensemble of N parallel dipoles located, on average, uniformly are considered. For N → ∞, the problem is reduced to the Poisson problem. The direction of the dipoles specifies the symmetry axis of fluctuations. The moments of probability distributions for the Cartesian components of the strength are calculated. The anisotropy of the fluctuations is approximately 15–20%. Under conditions that are of interest for spectroscopic applications, the N-particle probability distribution contains a weak broad negative background, the shape of which replicates the one-particle distribution. The analogy between the problem considered and the theory of spectral line broadening in the impact approximation, in particular, the Dicke narrowing of the Doppler profile, is analyzed. Conditions of applicability of the theory developed are discussed.