Near-field backflow of energy

Abstract

Using the plane waves expansion, we derive all six components of the E- and H-vectors for an elliptically polarized optical vortex with the arbitrary topological charge. Relations to describe the distributions of intensity and components of the Poynting vector in the initial plane of the optical vortex are also derived. In a particular case of the narrow angular spectrum of circularly polarized plane waves (Bessel beams), it is shown that if inhomogeneous evanescent waves are presented in the initial light field, a near-axis reverse flow of radiation can occur. An angular optical tractor effect is also shown to occur in the initial plane, in which at different radii from the optical axis the transverse energy flow rotates either clockwise or anticlockwise. The general relations derived can also be used to analyze peculiarities of the light flow for other known exact solutions of Maxwell’s equations.