1,081 research outputs found
A quantum photonics model for non-classical light generation using integrated nanoplasmonic cavity-emitter systems
The implementation of non-classical light sources is becoming increasingly
important for various quantum applications. A particularly interesting approach
is to integrate such functionalities on a single chip as this could pave the
way towards fully scalable quantum photonic devices. Several approaches using
dielectric systems have been investigated in the past. However, it is still not
understood how on-chip nanoplasmonic antennas, interacting with a single
quantum emitter, affect the quantum statistics of photons reflected or
transmitted in the guided mode of a waveguide. Here we investigate a quantum
photonic platform consisting of an evanescently coupled nanoplasmonic
cavity-emitter system and discuss the requirements for non-classical light
generation. We develop an analytical model that incorporates quenching due to
the nanoplasmonic cavity to predict the quantum statistics of the transmitted
and reflected guided waveguide light under weak coherent pumping. The
analytical predictions match numerical simulations based on a master equation
approach. It is moreover shown that for resonant excitation the degree of
anti-bunching in transmission is maximized for an optimal cavity modal volume
and cavity-emitter distance . In reflection, perfectly anti-bunched
light can only be obtained for specific combinations. Finally, our
model also applies to dielectric cavities and as such can guide future efforts
in the design and development of on-chip non-classical light sources using
dielectric and nanoplasmonic cavity-emitter systems
Visible quantum plasmonics from metallic nanodimers
We report theoretical evidence that bulk nonlinear materials weakly
interacting with highly localized plasmonic modes in ultra-sub-wavelength
metallic nanostructures can lead to nonlinear effects at the single plasmon
level in the visible range. In particular, the two-plasmon interaction energy
in such systems is numerically estimated to be comparable with the typical
plasmon linewidths. Localized surface plasmons are thus predicted to exhibit a
purely nonclassical behavior, which can be clearly identified by a
sub-Poissonian second-order correlation in the signal scattered from the
quantized plasmonic field under coherent electromagnetic excitation. We
explicitly show that systems sensitive to single-plasmon scattering can be
experimentally realized by combining electromagnetic confinement in the
interstitial region of gold nanodimers with local infiltration or deposition of
ordinary nonlinear materials. We also propose configurations that could allow
to realistically detect such an effect with state-of-the-art technology,
overcoming the limitations imposed by the short plasmonic lifetime
A single-photon transistor using nano-scale surface plasmons
It is well known that light quanta (photons) can interact with each other in
nonlinear media, much like massive particles do, but in practice these
interactions are usually very weak. Here we describe a novel approach to
realize strong nonlinear interactions at the single-photon level. Our method
makes use of recently demonstrated efficient coupling between individual
optical emitters and tightly confined, propagating surface plasmon excitations
on conducting nanowires. We show that this system can act as a nonlinear
two-photon switch for incident photons propagating along the nanowire, which
can be coherently controlled using quantum optical techniques. As a novel
application, we discuss how the interaction can be tailored to create a
single-photon transistor, where the presence or absence of a single incident
photon in a ``gate'' field is sufficient to completely control the propagation
of subsequent ``signal'' photons.Comment: 20 pages, 4 figure
Plasmonic Waveguides to Enhance Quantum Electrodynamic Phenomena at the Nanoscale
The emerging field of plasmonics can lead to enhanced light matter
interactions at extremely nanoscale regions. Plasmonic (metallic) devices
promise to efficiently control both classical and quantum properties of light.
Plasmonic waveguides are usually used to excite confined electromagnetic modes
at the nanoscale that can strongly interact with matter. The analysis of these
nanowaveguides exhibits similarities with their low frequency microwave
counterparts. In this article, we review ways to study plasmonic nanostructures
coupled to quantum optical emitters from a classical electromagnetic
perspective. These quantum emitters are mainly used to generate single photon
quantum light that can be employed as a quantum bit or qubit in the envisioned
quantum information technologies. We demonstrate different ways to enhance a
diverse range of quantum electrodynamic phenomena based on plasmonic
configurations by using the classical dyadic tensor Green function formalism.
More specifically, spontaneous emission and superradiance are analyzed by using
the Green function based field quantization. The exciting new field of quantum
plasmonics will lead to a plethora of novel optical devices for communications
and computing applications operating in the quantum realm, such as efficient
single-photon sources, quantum sensors, and compact on-chip nanophotonic
circuits
Interaction and coherence of a plasmon-exciton polariton condensate
Polaritons are quasiparticles arising from the strong coupling of
electromagnetic waves in cavities and dipolar oscillations in a material
medium. In this framework, localized surface plasmon in metallic nanoparticles
defining optical nanocavities have attracted increasing interests in the last
decade. This interest results from their sub-diffraction mode volume, which
offers access to extremely high photonic densities by exploiting strong
scattering cross-sections. However, high absorption losses in metals have
hindered the observation of collective coherent phenomena, such as
condensation. In this work we demonstrate the formation of a non-equilibrium
room temperature plasmon-exciton-polariton condensate with a long range spatial
coherence, extending a hundred of microns, well over the excitation area, by
coupling Frenkel excitons in organic molecules to a multipolar mode in a
lattice of plasmonic nanoparticles. Time-resolved experiments evidence the
picosecond dynamics of the condensate and a sizeable blueshift, thus measuring
for the first time the effect of polariton interactions in plasmonic cavities.
Our results pave the way to the observation of room temperature superfluidity
and novel nonlinear phenomena in plasmonic systems, challenging the common
belief that absorption losses in metals prevent the realization of macroscopic
quantum states.Comment: 23 pages, 5 figures, SI 7 pages, 5 figure
CHARACTERIZATION OF FLUORESCENCE FROM QUANTUM DOTS ON NANOSTRUCTURED METAL SURFACES
The behavior of fluorescent materials coupled to surface plasmon supporting surfaces and structures is an area of active research due to their fluorescence enhancing properties. The inherent field enhancements present near structures and interfaces where surface plasmons are excited provide great potential for increasing the response of many optical interactions. While many studies focus on the application of plasmonic nanoparticles or finite metallic structures the use of dielectric structures on a continuous metallic film has received little attention. A comprehensive experimental study using dielectric gratings on gold films is presented illustrating the fundamental properties of fluorescence enhancement on such structures. A process for fabrication of samples using Electron Beam Lithography is demonstrated and comparisons between various quantum dot deposition methods are made to determine the best conditions for surface coating. Conditions for optimization of the fluorescence enhancement phenomena for practical application are explored for gratings with square function profile illustrating the influence of gratings on fluorescence behavior and identifying conditions for optimal enhancement. Complementing these results, an understanding of the underlying physical phenomena is developed by differentiation between enhanced emission and enhanced absorption effects using measurements of fluorescence decay lifetime and emission spectra. Using these observations a thorough description of these systems and the requirements for their practical application is illustrated
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