A method for investigating the spatial correlation properties of a stochastic wave field

A method for studying the spatial correlation properties of a stochastic wave field with a wide angular spectrum based on a correlation analysis of the spatial distribution of the complex amplitude of this field formed using numerical simulation is proposed and tested. A comparison of the results of determining the transverse correlation properties of a monochromatic field in its various sections based on the proposed method with the results obtained based on analytical formulas showed their very good agreement. The distribution of the complex amplitude of the optical wave field with a wide angular spectrum of spatial harmonics was numerically simulated for various intervals of variation of the random initial phases of the harmonics in the range from 0 to 2 radians. The correlation properties of the fluctuation components of the generated disturbance fields in the lateral plane of the wave field are investigated numerically. It is established that the length of the lateral correlation of field fluctuations does not change with a variation of the interval of the initial phase difference. Studies have shown that the lateral spatial coherence – the shape of the coherence function and the length of the coherence, of a quasi-monochromatic wave field is determined by the numerical aperture value of the field and the shape of its angular spectrum.