321 research outputs found
Far-field optical microscope with nanometer-scale resolution based on in-plane surface plasmon imaging
A new far-field optical microscopy technique capable of reaching
nanometer-scale resolution has been developed recently using the in-plane image
magnification by surface plasmon polaritons. This microscopy is based on the
optical properties of a metal-dielectric interface that may, in principle,
provide extremely large values of the effective refractive index n up to
100-1000 as seen by the surface plasmons. Thus, the theoretical diffraction
limit on resolution becomes lambda/2n, and falls into the nanometer-scale
range. The experimental realization of the microscope has demonstrated the
optical resolution better than 50 nm for 502 nm illumination wavelength.
However, the theory of such surface plasmon-based far-field microscope
presented so far gives an oversimplified picture of its operation. For example,
the imaginary part of the metal dielectric constant severely limits the
surface-plasmon propagation and the shortest attainable wavelength in most
cases, which in turn limits the microscope magnification. Here I describe how
this limitation has been overcome in the experiment, and analyze the practical
limits on the surface plasmon microscope resolution. In addition, I present
more experimental results, which strongly support the conclusion of extremely
high spatial resolution of the surface plasmon microscope.Comment: 23 pages, 9 figures, will be published in the topical issue on
Nanostructured Optical Metamaterials of the Journal of Optics A: Pure and
Applied Optics, Manuscript revised in response to referees comment
Metamaterial model of tachyonic dark energy
Dark energy with negative pressure and positive energy density is believed to
be responsible for the accelerated expansion of the universe. Quite a few
theoretical models of dark energy are based on tachyonic fields interacting
with itself and normal (bradyonic) matter. Here we propose an experimental
model of tachyonic dark energy based on hyperbolic metamaterials. Wave equation
describing propagation of extraordinary light inside hyperbolic metamaterials
exhibits 2+1 dimensional Lorentz symmetry. The role of time in the
corresponding effective 3D Minkowski spacetime is played by the spatial
coordinate aligned with the optical axis of the metamaterial. Nonlinear optical
Kerr effect bends this spacetime resulting in effective gravitational force
between extraordinary photons. We demonstrate that this model has a
self-interacting tachyonic sector having negative effective pressure and
positive effective energy density. Moreover, a composite multilayer SiC-Si
hyperbolic metamaterial exhibits closely separated tachyonic and bradyonic
sectors in the long wavelength infrared range. This system may be used as a
laboratory model of inflation and late time acceleration of the universe.Comment: 10 pages, 2 figures. This version is accepted for publication in the
special issue of Galaxies: Beyond Standard Gravity and Cosmolog
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
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