Space-time Spectrum Correlation Function of the Dynamic Polychromatic Laser Speckle

This paper theoretically analyses the normalized space-time spectrum correlation function of the time-varying polychromatic laser speckle intensity fluctuation produced in the Fraunhofer diffraction field by a moving diffuse object. It is found that the space-time spectrum correlation function strongly depends on both the spatial non-stationarity of an elongated speckle pattern and the movement of the diffuse object. The theoretical results obtained are confirmed by experiments.