Polarization coverage and self-healing characteristics of Poincar\'e-Bessel beam

TL;DR

This paper provides a comprehensive theoretical and experimental analysis of Poincaré-Bessel beams, revealing their polarization properties, singularity dynamics, and self-healing capabilities, with potential applications in imaging and atmospheric studies.

Contribution

It offers the first detailed investigation of the polarization characteristics and singularity dynamics of Poincaré-Bessel beams, including their self-healing behavior and polarization coverage.

Findings

PBBs have polarization coverage >75% on the Poincaré sphere.

PBBs exhibit resilience of polarization degree under perturbation.

Singularity dynamics involve creation and recombination during self-healing.

Abstract

As a vector version of scalar Bessel beams, Poincar\'{e}-Bessel beams (PBBs) have attracted a great deal of attention due to the presence of polarization singularities and their nondiffraction and self-healing properties. Previous studies of PBBs have been restricted primarily to understanding the disinclination patterns in the spatially variable polarization, and many of the properties of PBBs remain unexplored. Here, we present a theoretical and experimental study of the polarization characteristics of PBBs, investigating a variety of their features. Using a mode transformation of a full Poincar\'{e} (FP) beam in a rectangular basis, ideally carrying 100$\%$ polarization coverage of polarization states represented on the surface of the Poincar\'{e} sphere, we observe the PBB as the superposition of an infinite number of FP beams, as each ring of PBB has polarization coverage >75$\%$. We also observe the resilience of a PBB's degree of polarization to perturbation. The polarization-ellipse orientation map of PBBs shows the presence of infinite series of C-point singularity pairs. The number of such series pairs is decided by the number of C-point singularity pairs of the FP beam. The dynamics of C-point singularity pairs in the self-healing process show a non-trivial creation of new singularities and recombination of existing singularities. Such dynamics provide insight into ``Hilbert Hotel'' style evolution of singularities in light beams. The present study can be useful for imaging in the presence of depolarizing surroundings, studying turbulent atmospheric channels, and exploring the rich mathematical concepts of transfinite numbers.