5 research outputs found
Unravelling Nonlinear Spectral Evolution Using Nanoscale Photonic Near-Field Point-to-Point Measurements
We
demonstrate nanoscale photonic point-to-point measurements characterizing
a single component inside an all-optical signal-processing chip. We
perform spectrally resolved near-field scanning optical microscopy
on ultrashort pulses propagating inside a slow light photonic crystal
waveguide, which is part of a composite sample. A power study reveals
a reshaping of the pulse’s spectral density, which we model
using the nonlinear Schrödinger equation. With the model, we
are able to identify the various physical processes governing the
nonlinear pulse propagation. Finally, we contrast the near-field measurements
with transmission measurements of the complete composite sample to
elucidate the importance of gaining local information about the evolution
of the spectral density
Supplement 1: Tracking nanoscale electric and magnetic singularities through three-dimensional space
Originally published in Optica on 20 June 2015 (optica-2-6-540
Harmonics Generation by Surface Plasmon Polaritons on Single Nanowires
We present experimental
observations of visible wavelength second-
and third-harmonic generation on single plasmonic nanowires of variable
widths. We identify that near-infrared surface plasmon polaritons,
which are guided along the nanowire, act as the source of the harmonics
generation. We discuss the underlying mechanism of this nonlinear
process, using a combination of spatially resolved measurements and
numerical simulations to show that the visible harmonics are generated
via a combination of both local and propagating plasmonic modes. Our
results provide the first demonstration of nanoscale nonlinear optics
with guided, propagating plasmonic modes on a lithographically defined
chip, opening up new routes toward integrated optical circuits for
information processing
Core–Shell Plasmonic Nanohelices
We introduce core–shell plasmonic
nanohelices, highly tunable
structures that have a different response in the visible for circularly
polarized light of opposite handedness. The glass core of the helices
is fabricated using electron beam induced deposition and the pure
gold shell is subsequently sputter coated. Optical measurements allow
us to explore the chiral nature of the nanohelices, where differences
in the response to circularly polarized light of opposite handedness
result in a dissymmetry factor of 0.86, more than twice of what has
been previously reported. Both experiments and subsequent numerical
simulations demonstrate the extreme tunability of the core–shell
structures, where nanometer changes to the geometry can lead to drastic
changes of the optical responses. This tunability, combined with the
large differential transmission, make core–shell plasmonic
nanohelices a powerful nanophotonic tool for, for example, (bio)Âsensing
applications
Chip-Based All-Optical Control of Single Molecules Coherently Coupled to a Nanoguide
The
feasibility of many proposals in nanoquantum-optics depends
on the efficient coupling of photons to individual quantum emitters,
the possibility to control this interaction on demand, and the scalability
of the experimental platform. To address these issues, we report on
chip-based systems made of one-dimensional subwavelength dielectric
waveguides (nanoguides) and polycyclic aromatic hydrocarbon molecules.
We discuss the design and fabrication requirements, present data on
extinction spectroscopy of single molecules coupled to a nanoguide
mode, and show how an external optical beam can switch the propagation
of light via a nonlinear optical process. The presented architecture
paves the way for the investigation of many-body phenomena and polaritonic
states and can be readily extended to more complex geometries for
the realization of quantum integrated photonic circuits