Correlation Measurements on Partially Coherent Beams by Means of an Integration Technique

Abstract
A method based on the measurement of the time-integrated irradiance obtained in an interference experiment is described. This method is of particular utility in cases in which amplitude and phase or both are stochastic fluctuating variables. When only phase fluctuations are present or when amplitude and phase are stochastic independent variables, simple relations can be derived from which the parameters of the distribution can be derived. In these cases, if a gaussian-distribution law for the phase fluctuations is assumed, the mean-square value of the phase fluctuations is directly measured. The method has been applied to the study of phase fluctuations of a laser beam, caused by atmospheric turbulence, with results that agree with the findings of other techniques. The anisotropy of turbulence can also be evaluated.