Optical Poynting singularities of propagating and evanescent vector Bessel beams

TL;DR

This paper investigates the conditions and locations of Poynting vector singularities in propagating and evanescent vector Bessel beams, revealing their relation to phase and polarization singularities and identifying a special case of evanescent standing waves.

Contribution

It provides a detailed analysis of Poynting singularities in vector Bessel beams, including existence conditions and spatial distributions, highlighting a unique case of evanescent standing waves.

Findings

Poynting singularities occur on cylindrical surfaces around the beam axis.

Evanescent Bessel beams can have singularities at all spatial points in a standing wave form.

Poynting singularities include phase singularities and some polarization points.

Abstract

For propagating and evanescent vector Bessel beams, we study the singularities of the Poynting vector (Poynting singularities), at which the energy flux density turns to zero. Poynting singularities include all the phase singularities and some of polarization ones (L- and C-points). We reveal the existence conditions and positions of singularities, which are located at cylindrical surfaces around the beam axis. We mark the special case of the evanescent Bessel beam in the form of cylindrical standing wave, that is singular at any spatial point.