Experimental verification of phase discontinuities induced scintillation enhancement under weak perturbations

TL;DR

This paper experimentally demonstrates that phase discontinuities, specifically anisotropic dislocations, can enhance scintillation under weak turbulence, offering new insights into phase effects on beam propagation.

Contribution

It provides the first experimental verification of scintillation enhancement caused by phase discontinuities, highlighting the role of anisotropic dislocations in weak perturbation sensitivity.

Findings

Anisotropic dislocations are more sensitive to weak turbulence than isotropic dislocations.

Scintillation enhancement is caused by the combined effect of screw and edge dislocations.

Experimental results support phase discontinuity's influence on beam scintillation.

Abstract

We verify the existence of scintillation enhancement by measuring the scintillation index of a beam composed of two coherent Gaussian vortex beams with $\pm 1$ topological charges propagating through thermally induced turbulence. Further experimental research based on the reference wave interferometric method demonstrates that this phenomenon is caused by the combined effect of a screw dislocation and an infinitely extended edge dislocation, namely the impact of an anisotropic dislocation. The experimental results indicate that the anisotropic dislocation is more sensitive to weak perturbations than an isotropic screw dislocation and an infinitely extended edge dislocation, which means the anisotropic dislocation has potential for weak perturbation measurement. This phenomenon is instructive in further phase discontinuity research.