Analysis of Propagation Characteristics of a Partially Coherent Modified Anomalous Vortex Beam in Uniaxial Crystals

This work investigates the propagation dynamics and structural evolution of a partially coherent modified anomalous vortex beam (PCMAVB) in uniaxial crystals with optical axes orthogonal to the beam direction. An analytical expression is derived using the Huygens-Fresnel diffraction integral, numerical simulations are performed to analyze how the refractive index ratio η of the crystal, along with beam parameters, including the coherence length σ0, topological charge m, beam order n, and modification parameter δ, influences the beam's intensity profile. The results reveal rich beam dynamics, such as self-focusing, elliptical deformation, self-reconstruction, and the evolution of central dark or bright regions, all governed by the crystal’s birefringence and coherence properties. Notably, the beam’s shape is highly sensitive to the refractive index ratio, with elliptical rotation and axis-aligned stretching observed. Increasing the coherence length diminishes partial coherence effects, while variations in δ enhance beam confinement. The study also demonstrates that the central dark core of the PCMAVB depends primarily on the topological charge, while increasing the beam order leads to more intricate intensity distribution. Moreover, the PCMAVB encompass several structured beam types as limiting cases depending on the values of m, n and δ. These findings offer valuable insights for applications in beam shaping, optical trapping, and propagation control in anisotropic media.