Correlations in scattered perfect optical vortices

We study correlations in the speckle patterns generated by scattering of perfect optical vortex (POV) beams and use them to produce a new class coherence functions, namely Bessel functions. Higher (zeroth) order functions have been realized cross (auto)-correlation between different orders. also studied propagation produced characterized their divergence with respect radius first ring for orders m = 0–4. observe that varies linearly function. provide exact analytical expression auto-correlation, as well cross-correlation patterns. Our experimental results are good agreement results.