Study of spiral-ring plasmonic structures for optical manipulation

Abstract

Chiral plasmonic structures provide an effective way to couple optical spin with orbital angular momentum, which is suitable to perform manipulation of light beam. This work presents simulation results for a type of spiral-ring plasmonic structures that provide circular polarization selectively in the visible spectrum. The structure consists of discrete spiral gratings that are truncated by rings. With circular polarized lights transmitting the subwavelength structure, surface plasmon polaritons and localized surface plasmons are excited together. Thus, multi-rings spiral plasmonic structures are introduced to obtain high extinction ratio circular dichroism. Moreover, the wavefront phase singularity is also observed in the simulation.

Review of the Functions of Archimedes’ Spiral Metallic Nanostructures

“…With the development of the ASS structures, Bo Yan et al presented a new aberrance based on the algebraic formula of simple ASS [ 54 ]. The chiral metallic spiral-ring structure contains discrete metallic slits with curved edges whose top view is depicted in Figure 14 .…”

“…The metallic spiral ring with a 200-nm inner radius r 1 and a 400-nm outer radius r 2 was etched through a 200-nm gold film deposited on the silica substrate. Reproduced with permission from [ 54 ]. Copyright Society of Photo-Optical Instrumentation Engineer, 2014.…”

“…The field intensity is calculated through an aperture with a radius of 200 nm, which is located 100 nm from the gold surface. Reproduced with permission from [ 54 ]. Copyright Society of Photo-Optical Instrumentation Engineer, 2014.…”