Optical Vortices during a Super-Resolution Process in a Metamaterial

TL;DR

This paper investigates the formation of optical vortices and phase singularities during a super-resolution process in a metamaterial lens, revealing a topologically stable saddle-vortex-saddle structure that influences energy flow.

Contribution

It introduces the topological structure of phase singularities and vortices in super-resolution through metamaterials, explaining energy flux behavior outside the lens.

Findings

Formation of a phase singularity saddle point outside the lens

Presence of two vortices connected to the saddle point

Control of power flow circulation by adjusting object position

Abstract

We show that a super-resolution process with 100% visibility is characterized by the formation of a point of phase singularity in free space outside the lens in the form of a saddle with topological charge equal to -1. The saddle point is connected to two vortices at the end boundary of the lens, and the two vortices are in turn connected to another saddle point inside the lens. The structure saddle-vortices-saddle is topologically stable. The formation of the saddle point in free space explains also the negative flux of energy present in a certain region of space outside the lens. The circulation strength of the power flow can be controlled by varying the position of the object plane with respect to the lens.