Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
Correlation functions and spectra for fields with highly anticorrelated phase jumps
Abraham G. Kofman
Abstract
A non-Markovian jump model of phase-fluctuating electromagnetic fields is considered, which is a generalization of the random phase telegraph model. According to the present model, the phase jumps are highly anticorrelated Markovian jump process, i.e., they have alternating signs and approximately equal magnitudes. Closed analytical results for the field correlation function and spectrum have been obtained under rather general assumptions. The parameter \ensuremath{\gamma}, which is a measure of correlation of successive jumps, has been expressed in a general form through the parameters of the model. Two regimes have been found, depending on the values of the rms phase jump B and the correlation parameter \ensuremath{\gamma}. For highly anticorrelated and not very large jumps (1+\ensuremath{\gamma}\ensuremath{\ll}1,${\mathit{B}}^{\mathrm{\ensuremath{-}}2}$) the correlation function (spectrum) consists of two components with significantly different damping rates (widths). In the opposite case each phase jump destroys the coherence of the field and the decay rate of the correlation function is determined by the frequency of jumps. The possibility of extracting parameters of the model from measurements of the laser field correlation function and/or spectrum is discussed.