529 research outputs found
Quantitative analysis of TM lateral leakage in foundry fabricated silicon Rib waveguides
We show that thin, shallow ridge, silicon-on-insulator waveguides exhibiting a lateral leakage behavior can be designed and fabricated using a standard silicon photonic foundry platform. We analyze the propagation loss through the observation of the transmitted TM polarized guided mode and TE polarized radiation and experimentally demonstrate that propagation losses as low as 0.087 dB/mm can be achieved. This demonstration will open a new frontier for practical devices exploiting a lateral leakage behavior with potential applications in the fields of biosensing and quantum optics among others
Frequency conversion between UV and telecom wavelengths in a lithium niobate waveguide for quantum communication with Yb+ trapped ions
We study and demonstrate the frequency conversion of UV radiation, resonant
with 369.5 nm transition in Yb+ ions to the C-band wavelength 1580.3 nm and
vice-versa using a reverse proton-exchanged waveguide in periodically poled
lithium niobate. Our integrated device can interface trapped Yb+ ions with
telecom infrastructure for the realization of an Yb+ based quantum repeater
protocol and to efficiently distribute entanglement over long distances. We
analyse the single photon frequency conversion efficiency from the 369.525 nm
to the telecom wavelength and its dependence on pump power, device length and
temperature. The single-photon noise generated by spontaneous Raman scattering
of the pump is also measured. From this analysis we estimate a single photon
conversion efficiency of 9% is achievable with our technology with almost
complete suppression of the Raman noise.Comment: 6 pages, 5 figure
Optical chirality from dark-field illumination of planar plasmonic nanostructures
Dark-field illumination is shown to make planar chiral nanoparticle
arrangements exhibit circular dichroism in extinction analogous to true chiral
scatterers. Circular dichrosim is experimentally observed at the maximum
scattering of single oligomers consisting rotationally symmetric arrangements
of gold nanorods, with strong agreement to numerical simulation. A dipole model
is developed to show that this effect is caused by a difference in the
geometric projection of a nanorod onto the handed orientation of electric
fields created by a circularly polarized dark-field that is normally incident
on a glass substrate. Owing to this geometric origin, the wavelength of the
peak chiral response is also experimentally shown to shift depending on the
separation between nanoparticles. All presented oligomers have physical
dimensions less than the operating wavelength, and the applicable extension to
closely packed planar arrays of oligomers is demonstrated to amplify the
magnitude of circular dichroism. The realization of strong chirality in these
oligomers demonstrates a new path to engineer optical chirality from planar
devices using dark-field illumination
High-order Radio Frequency Differentiation via Photonic Signal Processing with an Integrated Micro-resonator Kerr Optical Frequency Comb Source
We demonstrate the use of integrated micro-resonator based optical frequency
comb sources as the basis for transversal filtering functions for microwave and
radio frequency photonic filtering and advanced functions.Comment: 8 pages, 7 figures, 46 References. arXiv admin note: substantial text
overlap with arXiv:1512.01741, arXiv:1512.0630
Emerging applications of integrated optical microcombs for analogue RF and microwave photonic signal processing
We review new applications of integrated microcombs in RF and microwave
photonic systems. We demonstrate a wide range of powerful functions including a
photonic intensity high order and fractional differentiators, optical true time
delays, advanced filters, RF channelizer and other functions, based on a Kerr
optical comb generated by a compact integrated microring resonator, or
microcomb. The microcomb is CMOS compatible and contains a large number of comb
lines, which can serve as a high performance multiwavelength source for the
transversal filter, thus greatly reduce the cost, size, and complexity of the
system. The operation principle of these functions is theoretically analyzed,
and experimental demonstrations are presented.Comment: 16 pages, 8 figures, 136 References. Photonics West 2018 invited
paper, expanded version. arXiv admin note: substantial text overlap with
arXiv:1710.00678, arXiv:1710.0861
Search for high-performance probe-fed stacked patches using optimization
High-performance circular probe-fed stacked patch antenna designs are explored through the use of numerical optimization. New trends are sought to aid understanding and to suggest novel solutions. We describe the optimization technique, present a new design trend relating efficiency and bandwidth to the choice of substrate dielectric, and propose and demonstrate a novel, optimized antenna achieving 33% bandwidth whilst maintaining greater than 80% surface wave efficiency
Photonic RF and microwave reconfigurable filters and true time delays based on an integrated optical Kerr frequency comb source
We demonstrate advanced transversal radio frequency (RF) and microwave
functions based on a Kerr optical comb source generated by an integrated
micro-ring resonator. We achieve extremely high performance for an optical true
time delay aimed at tunable phased array antenna applications, as well as
reconfigurable microwave photonic filters. Our results agree well with theory.
We show that our true time delay would yield a phased array antenna with
features that include high angular resolution and a wide range of beam steering
angles, while the microwave photonic filters feature high Q factors, wideband
tunability, and highly reconfigurable filtering shapes. These results show that
our approach is a competitive solution to implementing reconfigurable, high
performance and potentially low cost RF and microwaveComment: 15 pages, 11 Figures, 60 Reference
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