10,658 research outputs found
Plasmonic Metamaterials: Physical Background and Some Technological Applications
New technological frontiers appear every year, and few are as intriguing as the field of plasmonic metamaterials (PMMs). These uniquely designed materials use coherent electron oscillations to accomplish an astonishing array of tasks, and they present diverse opportunities in many scientific fields.
This paper consists of an explanation of the scientific background of PMMs and some technological applications of these fascinating materials. The physics section addresses the foundational concepts necessary to understand the operation of PMMs, while the technology section addresses various applications, like precise biological and chemical sensors, cloaking devices for several frequency ranges, nanoscale photovoltaics, experimental optical computing components, and superlenses that can surpass the diffraction limit of conventional optics
A comparative study of semiconductor-based plasmonic metamaterials
Recent metamaterial (MM) research faces several problems when using
metal-based plasmonic components as building blocks for MMs. The use of
conventional metals for MMs is limited by several factors: metals such as gold
and silver have high losses in the visible and near-infrared (NIR) ranges and
very large negative real permittivity values, and in addition, their optical
properties cannot be tuned. These issues that put severe constraints on the
device applications of MMs could be overcome if semiconductors are used as
plasmonic materials instead of metals. Heavily doped, wide bandgap oxide
semiconductors could exhibit both a small negative real permittivity and
relatively small losses in the NIR. Heavily doped oxides of zinc and indium
were already reported to be good, low loss alternatives to metals in the NIR
range. Here, we consider these transparent conducting oxides (TCOs) as
alternative plasmonic materials for many specific applications ranging from
surface-plasmon-polariton waveguides to MMs with hyperbolic dispersion and
epsilon-near-zero (ENZ) materials. We show that TCOs outperform conventional
metals for ENZ and other MM-applications in the NIR.Comment: 16 pages, 7 figure
Modeling of Time with Metamaterials
Metamaterials have been already used to model various exotic "optical
spaces". Here we demonstrate that mapping of monochromatic extraordinary light
distribution in a hyperbolic metamaterial along some spatial direction may
model the "flow of time". This idea is illustrated in experiments performed
with plasmonic hyperbolic metamaterials. Appearance of the "statistical arrow
of time" is examined in an experimental scenario which emulates a Big Bang-like
event.Comment: 15 pages, 4 figures, this version is accepted for publication in JOSA
Optical Nanotransmission Lines: Synthesis of Planar Left-Handed Metamaterials in the Infrared and Visible Regimes
Following our recent theoretical development of the concept of
nano-inductors, nano-capacitors and nano-resistors at optical frequencies and
the possibility of synthesizing more complex nano-scale circuits, here we
theoretically investigate in detail the problem of optical
nano-transmission-lines (NTL) that can be envisioned by properly joining
together arrays of these basic nano-scale circuit elements. We show how, in the
limit in which these basic circuit elements are closely packed together, the
NTLs can be regarded as stacks of plasmonic and non-plasmonic planar slabs,
which may be designed to effectively exhibit the properties of planar
metamaterials with forward (right-handed) or backward (left-handed) operation.
With the proper design, negative refraction and left-handed propagation are
shown to be possible in these planar plasmonic guided-wave structures,
providing possibilities for sub-wavelength focusing and imaging in planar
optics, and laterally-confined waveguiding at IR and visible frequencies. The
effective material parameters for such NTLs are derived, and the connection and
analogy between these optical NTLs and the double-negative and double-positive
metamaterials are also explored. Physical insights and justification for the
results are also presented.Comment: 26 pages, 12 figures, accepted for publication in JOSA B, scheduled
to appear March 200
Experimental Modeling of Cosmological Inflation with Metamaterials
Recently we demonstrated that mapping of monochromatic extraordinary light
distribution in a hyperbolic metamaterial along some spatial direction may
model the flow of time and create an experimental toy model of the big bang.
Here we extend this model to emulate cosmological inflation. This idea is
illustrated in experiments performed with two-dimensional plasmonic hyperbolic
metamaterials. Spatial dispersion which is always present in hyperbolic
metamaterials results in scale-dependent (fractal) structure of the
inflationary "metamaterial spacetime". This feature of our model replicates
hypothesized fractal structure of the real observable universe.Comment: 17 pages, 3 figures. This version is accepted for publication in
Physics Letters
Plasmonic nanoparticle monomers and dimers: From nano-antennas to chiral metamaterials
We review the basic physics behind light interaction with plasmonic
nanoparticles. The theoretical foundations of light scattering on one metallic
particle (a plasmonic monomer) and two interacting particles (a plasmonic
dimer) are systematically investigated. Expressions for effective particle
susceptibility (polarizability) are derived, and applications of these results
to plasmonic nanoantennas are outlined. In the long-wavelength limit, the
effective macroscopic parameters of an array of plasmonic dimers are
calculated. These parameters are attributable to an effective medium
corresponding to a dilute arrangement of nanoparticles, i.e., a metamaterial
where plasmonic monomers or dimers have the function of "meta-atoms". It is
shown that planar dimers consisting of rod-like particles generally possess
elliptical dichroism and function as atoms for planar chiral metamaterials. The
fabricational simplicity of the proposed rod-dimer geometry can be used in the
design of more cost-effective chiral metamaterials in the optical domain.Comment: submitted to Appl. Phys.
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