364 research outputs found
Fundamental Limits for Light Absorption and Scattering Induced by Cooperative Electromagnetic Coupling
Absorption and scattering of electromagnetic waves by dielectric media are of
fundamental importance in many branches of physics. In this Letter we
analytically derived the ultimate upper limits for the absorbed and scattered
powers by any system of optical resonators in mutual interaction. We show that
these bounds depend only on the geometric configuration given an incident
field. We give the conditions to fullfill to reach these limits paving so a way
for a rational design of optimal metamaterials
Proposal for compact solid-state III-V single-plasmon sources
We propose a compact single-plasmon source operating at near-infrared
wavelengths on an integrated III-V semiconductor platform, with a thin ridge
waveguide serving as the plasmon channel. By attaching an ultra-small cavity to
the channel, it is shown that both the plasmon generation efficiency ({\beta})
and the spontaneous-decay rate into the channel can be significantly enhanced.
An analytical model derived with the Lorentz reciprocity theorem captures the
main physics involved in the design of the source and yields results in good
agreement with fully-vectorial simulations of the device. At resonance, it is
predicted that the ultra-small cavity increases the {\beta}-factor by 70% and
boosts the spontaneous decay rate by a factor 20. The proposed design could
pave the way towards integrated and scalable plasmonic quantum networks.
Comparison of the present design with other fully-dielectric competing
approaches is addressed.Comment: 8 pages, 4 figure
A surface-scattering model satisfying energy conservation and reciprocity
In order for surface scattering models to be accurate they must necessarily
satisfy energy conservation and reciprocity principles. Roughness scattering
models based on Kirchoff's approximation or perturbation theory do not satisfy
these criteria in all frequency ranges. Here we present a surface scattering
model based on analysis of scattering from a layer of particles on top of a
substrate in the dipole approximation which satisfies both energy conservation
and reciprocity and is thus accurate in all frequency ranges. The model takes
into account the absorption in the substrate induced by the particles but does
not take into account the near-field interactions between the particles.Comment: 15 pages, 10 figure
RETICOLO software for grating analysis
RETICOLO implements the rigorous coupled wave analysis (RCWA) for 1D
(classical and conical diffraction) and 2D crossed gratings. It operates under
a MATLAB environment and incorporates an efficient and accurate toolbox for
computing Bloch modes and visualizing the electromagnetic field in the grating
region. As a spin-off, the Version V9 launched in 2021 includes a toolbox for
the analysis of stacks of arbitrarily anisotropic multilayered thin-films
Polaritonic modes in a dense cloud of atoms
We analyze resonant light scattering by an atomic cloud in a regime where
near-field interactions between scatterers cannot be neglected. We first use a
microscopic approach and calculate numerically the eigenmodes of the cloud for
many different realizations. It is found that there always exists a small
number of polaritonic modes that are spatially coherent and superradiant. We
show that scattering is always dominated by these modes. We then use a
macroscopic approach by introducing an effective permittivity so that the
atomic cloud is equivalent to a dielectric particle. We show that there is a
one-to-one correspondence between the microscopic polaritonic modes and the
modes of a homogeneous particle with an effective permittivity
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