A long focal depth plasmonic lens with a wedge-shaped inclined slit

Abstract

The patent of the present invention discloses a plasmonic lens with a wedge-shaped inclined slit and a long focal depth. The wedge-shaped inclined slit long focal depth plasmonic lens is formed by constructing a central slit with a vertical uniform width on a planar metal film and a wedge-shaped inclined slit symmetrical to the left and right of the central slit; Under the condition of vertical incidence, the focusing effect of long focal depth can be achieved. In the structure, the central slit is selected as the lens symmetry axis, and the wedge-shaped inclined slits are symmetrical to the central slit in pairs, and the incident surface ends are inclined outward relative to the central slit, and the outer slits are inclined The larger the angle is, the wider the incident end of the slit is than the outgoing end, and the inclination angle of the symmetrical slit wall, the inclination angle of the outer wall and the width are the same; the wedge-shaped inclined slit metal film lens realizes the transverse magnetic line of the planar metal plasmon lens The focusing effect of polarized light with a long focal depth. The lens of the invention has a compact structure, is convenient for preparation and actual production, and has good application prospects in the fields of optical micro-manipulation, optical micro-processing and the like.

Description

technical field [0001] The invention belongs to the field of subwavelength photonics and integrated optics, in particular to a transverse magnetic linearly polarized light focusing lens based on the plasmon effect. Background technique [0002] Surface plasmon polaritons (SPPs), the coupling of collective electron oscillations of electromagnetic waves (EW) propagating at interfaces between metals and dielectrics, have been rapidly developed in the past 10 years. Because of their excellent properties, they offer great potential for controlling beam propagation and modulating the distribution of light fields at the nanoscale, and have attracted extensive attention in this field. An increasing number of plasmonic components have been proposed to achieve various functions and have shown promising performances in both simulations and experiments. [0003] Surface plasmons can break through the diffraction limit and have strong local field enhancement characteristics, which can r...

AI Technical Summary

Problems solved by technology

Hongyan Shao et al. published in the journal "Plasmonics" in 2016 entitled "Plasmonic Planar Lens Based on Slanted Nanolist Array" proposed a planar metal lens structure that can achieve tight focusing of linearly polarized light, overcoming the structure of curved lenses Difficult, but there is still a lot of room for optimization in its focusing effect such as the depth of focus

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