8 research outputs found
The Effect of Metal Thickness on Si Wire to Plasmonic Slot Waveguide Mode Conversion
We investigate mode converters for Si wire to plasmonic slot waveguides at
1550 nm telecom wavelength. The structures are based on a taper geometry. We
provide optimal dimensions with more than 90% power transmission for a range of
metal (Au) thicknesses between 30-250 nm. We provide details on how to
differentiate between the total power and the power in the main mode of the
plasmonic slot waveguide. Our analysis is based on the orthogonality of modes
of the slot waveguide subject to a suitable inner product definition. Our
results are relevant for lowering the insertion loss and the bit error rate of
plasmonic modulators.Comment: 4 pages, 7 figures, 2 tables, preprint version of the published
paper, includes only the English abstrac
Few photon transport in a waveguide coupled to a pair of collocated two-level atoms
We calculate the one- and two-photon scattering matrices of a pair of
collocated non-identical two-level atoms coupled to a waveguide. We show that
by proper choice of a two-photon input, the background fluorescence by the
atoms may be completely quenched, as a result of quantum interference, and that
when the atoms' detuning is smaller than their linewidths, extremely narrow
fluorescence features emerge. Furthermore, the system emits a two-photon bound
state which can display spatial oscillations/quantum beats, and can be tuned
from bunched to anti-bunched statistics as the total photon energy is varied
Resonance fluorescence in a waveguide geometry
We show how to calculate the first- and second-order statistics of the
scattered fields for an arbitrary intensity coherent state light field
interacting with a two-level system in a waveguide geometry. Specifically, we
calculate the resonance fluorescence from the qubit, using input-output
formalism. We derive the transmission and reflection coefficients, and
illustrate the bunching and anti-bunching of light that is scattered in the
forward and backward directions, respectively. Our results agree with previous
calculations on one- and two-photon scattering as well as those that are based
on the master equation approach.Comment: 8 pages, 3 figures and supplementary material (Mathematica code).
This is the published version: typos are fixed, conclusion section is
expanded, references are update
Modal Analysis and Coupling in Metal-Insulator-Metal Waveguides
This paper shows how to analyze plasmonic metal-insulator-metal waveguides
using the full modal structure of these guides. The analysis applies to all
frequencies, particularly including the near infrared and visible spectrum, and
to a wide range of sizes, including nanometallic structures. We use the
approach here specifically to analyze waveguide junctions. We show that the
full modal structure of the metal-insulator-metal (MIM) waveguides--which
consists of real and complex discrete eigenvalue spectra, as well as the
continuous spectrum--forms a complete basis set. We provide the derivation of
these modes using the techniques developed for Sturm-Liouville and generalized
eigenvalue equations. We demonstrate the need to include all parts of the
spectrum to have a complete set of basis vectors to describe scattering within
MIM waveguides with the mode-matching technique. We numerically compare the
mode-matching formulation with finite-difference frequency-domain analysis and
find very good agreement between the two for modal scattering at symmetric MIM
waveguide junctions. We touch upon the similarities between the underlying
mathematical structure of the MIM waveguide and the PT symmetric quantum
mechanical pseudo-Hermitian Hamiltonians. The rich set of modes that the MIM
waveguide supports forms a canonical example against which other more
complicated geometries can be compared. Our work here encompasses the microwave
results, but extends also to waveguides with real metals even at infrared and
optical frequencies.Comment: 17 pages, 13 figures, 2 tables, references expanded, typos fixed,
figures slightly modifie