1,160 research outputs found
Mirrorless Negative-index Parametric Micro-oscillator
The feasibility and extraordinary properties of mirrorless parametric
oscillations in strongly absorbing negative-index metamaterials are shown. They
stem from the backwardness of electromagnetic waves inherent to this type of
metamaterials.Comment: 4 pages, 2 figure
Translation of Nanoantenna Hot-Spots by a Metal-Dielectric Composite Superlens
We employ numerical simulations to show that highly localized, enhanced
electromagnetic fields, also known as "hot spots," produced by a periodic array
of silver nanoantennas can be spatially translated to the other side of a
metal-dielectric composite superlens. The proposed translation of the hot spots
enables surface-enhanced optical spectroscopy without the undesirable contact
of molecules with metal, and thus it broadens and reinforces the potential
applications of sensing based on field-enhanced fluorescence and
surface-enhanced Raman scattering.Comment: 9 pages, 4 figure
Merging Nonlinear Optics and Negative-Index Metamaterials
The extraordinary properties of nonlinear optical propagation processes in
double-domain positive/negative index metamaterials are reviewed. These
processes include second harmonic generation, three- and four-wave frequency
mixing, and optical parametric amplification. Striking contrasts with the
properties of the counterparts in ordinary materials are shown. We also discuss
the possibilities for compensating strong losses inherent to plasmonic
metamaterials, which present a major obstacle in numerous exciting
applications, and the possibilities for creation of unique ultracompact
photonic devices such as data processing chips and nonlinear-optical sensors.
Finally, we propose similar extraordinary three-wave mixing processes in
crystals based on optical phonons with negative dispersion.Comment: A review paper, 27 pages, 16 figures, 81 reference
Colloidal Plasmonic Titanium Nitride Nanoparticles: Properties and Applications
Optical properties of colloidal plasmonic titanium nitride nanoparticles are
examined with an eye on their photothermal via transmission electron microscopy
and optical transmittance measurements. Single crystal titanium nitride cubic
nanoparticles with an average size of 50 nm exhibit plasmon resonance in the
biological transparency window. With dimensions optimized for efficient
cellular uptake, the nanoparticles demonstrate a high photothermal conversion
efficiency. A self-passivating native oxide at the surface of the nanoparticles
provides an additional degree of freedom for surface functionalization.Comment: 17 pages, 4 figures, 1 abstract figur
A Superlens Based on Metal-Dielectric Composites
Pure noble metals are typically considered to be the materials of choice for
a near-field superlens that allows subwavelength resolution by recovering both
propagating and evanescent waves. However, a superlens based on bulk metal can
operate only at a single frequency for a given dielectric host. In this Letter,
it is shown that a composite metal-dielectric film, with an appropriate metal
filling factor, can operate at practically any desired wavelength in the
visible and near-infrared ranges. Theoretical analysis and simulations verify
the feasibility of the proposed lens.Comment: 15 pages, 4 figure
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