Evolution of C-point singularities and polarization coverage of Poincaré-Bessel beam in self-healing process.

As a vector version of scalar Bessel beams, Poincaré-Bessel beams (PBBs) have attracted a great deal of attention due to their non-diffracting and self-healing properties as well as the presence of polarization singularities. Previous studies of PBBs have focused on cases that consist of a superposition of Bessel beams in orthogonal circular polarization states; here, we present a theoretical and experimental study of PBBs for which the polarization states are taken to be linear, which we call a linear PBB. Using a mode transformation of a full Poincaré beam constructed from linear polarization states, we observe the linear PBB as providing an in-principle infinite number of covers of the Poincaré sphere in the transverse plane and with an infinite number of C-points with positive and negative topological indices.

Orbital angular momentum spectrum of model partially coherent beams in turbulence.

The use of partial coherence has been extensively studied as a potential solution to mitigate the destructive effects of atmospheric turbulence in optical applications involving the free space propagation of light. However, in OAM-based optical systems, reducing coherence leads to the broadening of the orbital angular momentum (OAM) spectrum, consequently increasing the cross-talk between adjacent modes. In this paper, we have investigated three fundamental classes of partially coherent OAM beams under the influence of turbulence.

Circularly coherent vortex beams optimized for propagation through turbulence.

Self-focusing partially coherent beams with circular coherence have shown high potential for robust propagation through atmospheric turbulence. In this paper, we introduce a criterion to approximate the degrading effects of turbulence and we show how the coherence of the source can be optimized to generate a beam with the highest stability in turbulence. To test our prediction, we analytically compare the turbulence propagation of the OAM spectrum of circularly coherent Gaussian vortex sources with three different coherence parameters.

Modified Huygens-Fresnel method for the propagation of partially coherent beams through turbulence.

Partially coherent beams (PCBs) have been extensively studied as a method to mitigate the deleterious effects of atmospheric turbulence for applications such as free-space optical communication. However, it can be difficult to study and assess the performance of PCBs in turbulence due to the complicated physics of the atmosphere and the wide variety of PCBs possible. Here, we introduce a modified approach to study the propagation of second-order field moments of PCBs analytically in turbulence, reformulating the problem in terms of free-space propagation of the beam.