Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Controlling light polarization by swirling surface plasmons   Light polarization is a key aspect of modern optics. Current methods for
polarization control utilize birefringence and dichroism of anisotropic
materials or of arrays of anisotropically shaped nanostructures. Based on
collective optical effects, the resulting components remain much larger than
the wavelength of light, which limits design strategies. Here, we present a
travelling-wave plasmonic antenna that overcomes this limit using a gold-coated
helical nanowire non-radiatively fed with a dipolar aperture nanoantenna. Our
non-resonant hybrid nanoantenna enables tightly confined circularly polarized
light by swirling surface plasmons on the subwavelength scale and taking
advantage of optical spin-orbit interaction. Four closely packed circularly
polarized light sources of opposite handedness and tunable intensities are
demonstrated. By reaching near-field interaction between neighboring
nanoantennas, we obtain a highly miniaturized wave plate whose polarization
properties have never previously been demonstrated.

1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
21
The categories of this paper are: adap-org
10
The categories of this paper are: q-bio
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
4
The categories of this paper are: cond-mat
5
The categories of this paper are: gr-qc
26
The categories of this paper are: bayes-an