Focusing of light beyond the diffraction limit

TL;DR

This paper introduces a novel plasmonic lens that surpasses the diffraction limit, enabling light to be focused into a narrower line than traditionally possible, with potential for practical applications.

Contribution

The paper presents a new subwavelength plasmonic lens design that reduces diffraction limits by asymmetry, achieving super-resolution focusing beyond the near zone.

Findings

Focus width surpasses traditional diffraction limit

Fields are radiative and propagate to the far zone

Potential for new optical applications

Abstract

Diffraction limits the behaviour of light in optical systems and sets the smallest achievable line width at half the wavelength. With a novel subwavelength plasmonic lens to reduce the diffraction via an asymmetry and to generate and squeeze the wave functions, an incident light is focused by the aperture to a single-line with its width beyond the limit outside the near zone. The fields focused are radiative and capable of propagating to the far zone. The light focusing process, besides being of academic interest, is expected to open up a wide range of application possibilities.