441 research outputs found
Slow-light plasmonic metamaterial based on dressed-state analog of electromagnetically-induced transparency
We consider a simple configuration for realizing one-dimensional slow-light
metamaterials with large bandwidth-delay products using stub-shaped Fabry-Perot
resonators as building blocks. Each metaatom gives rise to large group indices
due to a classical analog of the dressed-state picture of
electromagnetically-induced transparency. By connecting up to eight metaatoms,
we find bandwidth-delay products over unity and group indices approaching 100.
Our approach is quite general and can be applied to any type of Fabry-Perot
resonators and tuned to different operating wavelengths
Quantum Emitters near Layered Plasmonic Nanostructures: Decay Rate Contributions
We introduce a numerical framework for calculating decay rate contributions
when excited two-level quantum emitters are located near layered plasmonic
nanostructures, particularly emphasizing the case of plasmonic nanostructures
atop metal substrates where three decay channels exist: free space radiation,
Ohmic losses, and excitation of surface plasmon polaritons (SPPs). The
calculation of decay rate contributions is based on Huygen's equivalence
principle together with a near-field to far-field transformation of the local
electric field, thereby allowing us to discern the part of the electromagnetic
field associated with free propagating waves rather than SPPs. The methodology
is applied to the case of an emitter inside and near a gap-plasmon resonator,
emphasizing strong position and orientation dependencies of the total decay
rate, contributions of different decay channels, radiation patterns, and
directivity of SPP excitation
Plasmonics for emerging quantum technologies
Expanding the frontiers of information processing technologies and, in
particular, computing with ever increasing speed and capacity has long been
recognized an important societal challenge, calling for the development of the
next generation of quantum technologies. With its potential to exponentially
increase computing power, quantum computing opens up possibilities to carry out
calculations that ordinary computers could not finish in the lifetime of the
Universe, while optical communications based on quantum cryptography become
completely secure. At the same time, the emergence of Big Data and the ever
increasing demands of miniaturization and energy saving technologies bring
about additional fundamental problems and technological challenges to be
addressed in scientific disciplines dealing with light-matter interactions. In
this context, quantum plasmonics represents one of the most promising and
fundamental research directions and, indeed, the only one that enables ultimate
miniaturization of photonic components for quantum optics when being taken to
extreme limits in light-matter interactions.Comment: To appear in Nanophotonic
Gradient metasurfaces: a review of fundamentals and applications
In the wake of intense research on metamaterials the two-dimensional
analogue, known as metasurfaces, has attracted progressively increasing
attention in recent years due to the ease of fabrication and smaller insertion
losses, while enabling an unprecedented control over spatial distributions of
transmitted and reflected optical fields. Metasurfaces represent optically thin
planar arrays of resonant subwavelength elements that can be arranged in a
strictly or quasi periodic fashion, or even in an aperiodic manner, depending
on targeted optical wavefronts to be molded with their help. This paper reviews
a broad subclass of metasurfaces, viz. gradient metasurfaces, which are devised
to exhibit spatially varying optical responses resulting in spatially varying
amplitudes, phases and polarizations of scattered fields. Starting with
introducing the concept of gradient metasurfaces, we present classification of
different metasurfaces from the viewpoint of their responses, differentiating
electrical-dipole, geometric, reflective and Huygens' metasurfaces. The
fundamental building blocks essential for the realization of metasurfaces are
then discussed in order to elucidate the underlying physics of various physical
realizations of both plasmonic and purely dielectric metasurfaces. We then
overview the main applications of gradient metasurfaces, including waveplates,
flat lenses, spiral phase plates, broadband absorbers, color printing,
holograms, polarimeters and surface wave couplers. The review is terminated
with a short section on recently developed nonlinear metasurfaces, followed by
the outlook presenting our view on possible future developments and
perspectives for future applications.Comment: Accepted for publication in Reports on Progress in Physic
Ultra-compact branchless plasmonic interferometers
Miniaturization of functional optical devices and circuits is a key
prerequisite for a myriad of applications ranging from biosensing to quantum
information processing. This development has considerably been spurred by rapid
developments within plasmonics exploiting its unprecedented ability to squeeze
light into subwavelength scale. In this study, we investigate on-chip plasmonic
systems allowing for synchronous excitation of multiple inputs and examine the
interference between two adjacent excited channels. We present a branchless
interferometer consisting of two parallel plasmonic waveguides that can be
either selectively or coherently excited via ultra-compact antenna couplers.
The total coupling efficiency is quantitatively characterized in a systematic
manner and shown to exceed 15% for small waveguide separations, with the power
distribution between the two waveguides being efficiently and dynamically
shaped by adjusting the incident beam position. The presented design principle
can readily be extended to other configurations, giving new perspectives for
highly dense integrated plasmonic circuitry, optoelectronic devices, and
sensing applications.Comment: 15 pages, 6 figure
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