Exact analysis of a Veselago lens in the quasi-static regime

TL;DR

This paper provides an exact analytical approach to studying Veselago lenses in the quasi-static regime, revealing unexpected field concentration effects and offering design insights for improved optical resolution.

Contribution

It introduces exact integral expressions for the electric potential in Veselago lenses, enabling precise analysis and revealing surprising field concentration phenomena.

Findings

Maximum electric field occurs at interfaces, not foci

Exact integral expressions facilitate lens design

Numerical results show enhanced resolution potential

Abstract

The resolution of conventional optical lenses is limited by the wavelength. Materials with negative refractive index have been shown to enable the generation of an enhanced resolution image where both propagating and non-propagating waves are employed. We analyze such a Veselago lens by exploiting some exact one dimensional integral expressions for the quasi-static electric potential of a point charge in that system. Those were recently obtained by expanding that potential in the quasi-static eigenfunctions of a three-flat-slabs composite structure. Numerical evaluations of those integrals, using realistic values for physical parameters like the electric permittivities of the constituent slabs and their thickness, reveal some surprising effects: E.g., the maximum concentration of the electric field occurs not at the geometric optics foci but at the interfaces between the negative permittivity slab and the positive permittivity slabs. The analysis provides simple computational guides for designing such structures in order to achieve enhanced resolution of an optical image.