Propagation intensity and phase distribution of a Partially Coherent Lorentz–Gauss Vortex Beam in a Gradient-Index Medium

Abstract

The study focused on examining the characteristics of partially coherent Lorentz-Gauss vortex beams in a medium featuring a gradient refractive index. The study employed the ABCD matrix, deriving analytical expressions for the cross-spectral density function based on the extended Huygens-Fresnel principle and the relationship between the Hermitian Gaussian function and Lorentz distribution. The findings revealed that the topological charge, coherence length, and gradient refractive index coefficient are pivotal factors influencing the beam’s behaviour in the medium. An increase in topological charge led to an expansion of the dark spot in intensity, while the gradient refractive index plays a crucial role in altering the size and shape of the intensity periodically in the medium and does not affect the dark spot in the middle of the beam. The findings from this study hold potential for applications in remote sensing and optical communications, making them valuable for further research endeavors.