144 research outputs found
Mobility of Discrete Solitons in Quadratically Nonlinear Media
We study the mobility of solitons in second-harmonic-generating lattices.
Contrary to what is known for their cubic counterparts, discrete quadratic
solitons are mobile not only in the one-dimensional (1D) setting, but also in
two dimensions (2D). We identify parametric regions where an initial kick
applied to a soliton leads to three possible outcomes, namely, staying put,
persistent motion, or destruction. For the 2D lattice, it is found that, for
the solitary waves, the direction along which they can sustain the largest kick
and can attain the largest speed is the diagonal. Basic dynamical properties of
the discrete solitons are also discussed in the context of an analytical
approximation, in terms of an effective Peierls-Nabarro potential in the
lattice setting.Comment: 4 page
Beam interactions in one-dimensional saturable waveguide arrays
The interaction between two parallel beams in one-dimensional discrete
saturable systems has been investigated using lithium niobate nonlinear
waveguide arrays. When the beams are separated by one channel and in-phase it
is possible to observe soliton fusion at low power levels. This new result is
confirmed numerically. By increasing the power, soliton-like propagation of
weakly-coupled beams occurs. When the beams are out-of-phase the most
interesting result is the existence of oscillations which resemble the recently
discovered Tamm oscillations.Comment: 5 pages, 6 figures, submitted to Phys. Rev.
Dynamics of quantum light in integrated nonlinear waveguide arrays and generation of robust continuous variable entanglement
We study a class of nonlinear waveguide arrays where the waveguides are
endowed with quadratic non- linearity and are coupled through the evanescent
overlap of the guided modes. We study both the stimulated and spontaneous
process in the array and show the viability of such an array as a platform for
generating both bipartite and tripartite continuous variable entanglement on
demand. We explicitly address the affect of realistic losses on the
entanglement produced, briefly discuss the possible types of nonlinear
materials that could be used, and suggest solutions to the possible phase
matching issues in the waveguides. The simultaneous generation and manipulation
of the light on a single waveguide chip circumvents the usual bandwidth
problems associated with the use of external bulky optical elements and makes
this avenue promising for further investigation.Comment: 5 pages, 5 figure
Fractional recurrence in discrete-time quantum walk
Quantum recurrence theorem holds for quantum systems with discrete energy
eigenvalues and fails to hold in general for systems with continuous energy. We
show that during quantum walk process dominated by interference of amplitude
corresponding to different paths fail to satisfy the complete quantum
recurrence theorem. Due to the revival of the fractional wave packet, a
fractional recurrence characterized using quantum P\'olya number can be seen.Comment: 10 pages, 11 figure : Accepted to appear in Central European Journal
of Physic
Nonlinear optics and light localization in periodic photonic lattices
We review the recent developments in the field of photonic lattices
emphasizing their unique properties for controlling linear and nonlinear
propagation of light. We draw some important links between optical lattices and
photonic crystals pointing towards practical applications in optical
communications and computing, beam shaping, and bio-sensing.Comment: to appear in Journal of Nonlinear Optical Physics & Materials (JNOPM
D 3. 3 Final performance results and consolidated view on the most promising multi -node/multi -antenna transmission technologies
This document provides the most recent updates on the technical contributions and research
challenges focused in WP3. Each Technology Component (TeC) has been evaluated
under possible uniform assessment framework of WP3 which is based on the simulation guidelines
of WP6. The performance assessment is supported by the simulation results which are in their
mature and stable state. An update on the Most Promising Technology Approaches (MPTAs)
and their associated TeCs is the main focus of this document. Based on the input of all the TeCs in WP3, a consolidated view of WP3 on the role of multinode/multi-antenna transmission
technologies in 5G systems has also been provided. This consolidated view is further
supported in this document by the presentation of the impact of MPTAs on METIS scenarios
and the addressed METIS goals.Aziz, D.; Baracca, P.; De Carvalho, E.; Fantini, R.; Rajatheva, N.; Popovski, P.; Sørensen, JH.... (2015). D 3. 3 Final performance results and consolidated view on the most promising multi -node/multi -antenna transmission technologies. http://hdl.handle.net/10251/7675
Multiple Quantum Well Directional Coupler with Photorefractive Grating
We analyse an asymmetric directional coupler with a thin photorefractive grating as a switching and demultiplexing element with memory. The grating is induced by two external beams interfering in the structure of AlGaAs/GaAs multiple quantum wells with an electric field applied along the quantum well planes
New tectonic elements in the Križna nappe between Bystra Valley and Strążyska Valley in the Tatra
The Sub-Tatric units was newly mapped for the implementation of the Detailed Geological Map of the Tatra Mountains at the scale of 1 : 10 000 (SmgT). Lithostratigraphic andtectonic field observations between the Bystra Valley and the Strążyska Valley allowed a newinterpretation of the geological structure of the area. The system of sheets has appeared to beeven more complicated than that advocated by Guzik and Kotański (1963). New sheets have been recognized: Grześkówki sheets (Lower and Upper sheets), which were distinguished from the former Grześkówki sheet (sensu Guzik & Kotański, 1963), and the Kazalnica sheet and Żywczańskie sheet, which were distinguished from the Samkowa Czuba sheet. Both Grześkówki sheets and Kazalnica sheet are composed of Carnian and Norian clastics or marly dolomites, Rhaetian limestones and Hettangian clayey-silty shales. The Lower Grzeoekówki and Kazalnica sheets lie in the inverted position and Żywczańskie sheet is composed of an isolated package of Lower Jurassic spotted marls and limestones lying in the normal position contrary to the inverted beds of the Samkowa Czuba sheet. The Spadowiec sheet has a wider spatial extent than it was postulated earlier. The Jastrzębia Turnia sheet probably does not exist in area between the valleys of Białego and Bystra
Direct Measurement Of Photonic Band Structures By Second Harmonic Generation
By exploiting the phase sensitivity of second harmonic generation, we measure photonic band structures in PLLN waveguide arrays. Furthermore, we show that the concept can be applied to other photonic structures, as, e.g., photonic crystals. © 2005 Optical Society of America
Multiple Quantum Well Directional Coupler With Photorefractive Grating
We analyse an asymmetric directional coupler with a thin photorefractive grating as a switching and demultiplexing element with memory. The grating is induced by two external beams interfering in the structure of AlGaAs/GaAs multiple quantum wells with an electric field applied along the quantum well planes
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