Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Excitation of epsilon-near-zero resonance in ultra-thin indium tin oxide
  shell embedded nanostructured optical fiber   We report a novel optical waveguide design of a hollow step index fiber
modified with a thin layer of indium tin oxide (ITO). We show an excitation of
highly confined waveguide mode in the proposed fiber near the wavelength where
permittivity of ITO approaches zero. Due to the high field confinement within
thin ITO shell inside the fiber, the epsilon-near-zero (ENZ) mode can be
characterized by a peak in modal loss of the hybrid waveguide. Our results show
that such in-fiber excitation of ENZ mode is due to the coupling of the guided
core mode to the thin-film ENZ mode. We also show that the phase matching
wavelength, where the coupling takes place, varies depending on the refractive
index of the constituents inside the central bore of the fiber. These ENZ
nanostructured optical fibers have many potential applications, for example, in
ENZ nonlinear and magneto-optics, as in-fiber wavelength-dependent filters, and
as subwavelength fluid channel for optical and bio-photonic sensing.

2
The categories of this paper are: math
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
6
The categories of this paper are: astro-ph
31
The categories of this paper are: ao-sci
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
0
The categories of this paper are: hep-ph
26
The categories of this paper are: bayes-an
1
The categories of this paper are: cs
9
The categories of this paper are: nlin
12
The categories of this paper are: nucl-th
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int