Search results for "GUIDES"
showing 10 items of 90 documents
Excitation and characterization of dielectric-loaded surface plasmon-polariton waveguides at telecommunication wavelengths - art. no. 69880T
2008
International audience; The excitation of surface plasmon-polariton (SPP) waveguide modes in 500-nm-wide and 550-nm-high dielectric ridges deposited on a thin gold film is characterized at telecommunication wavelengths, by application of a scanning near-field optical microscope (SNOM), and by utilizing the finite element method (FEM). Different tapering structures for coupling in SPPs, excited at the bare gold-air interface, are investigated with a SNOM, and the dependence of in coupling efficiency on tapering length is characterized by means of FEM calculations. The performance of this in coupling method is compared to an alternative excitation scheme, where the effective index of SPPs in …
Experimental demonstration and numerical study of plasmon-soliton waves
2019
Merging the fields of plasmonics and nonlinear optics authorizes a variety of fascinating and original physical phenomena. In this work, we specifically study the combination of the strong light confinement ability of surface plasmon polaritons (SPP) with the beam self-trapping effect in a nonlinear optical Kerr medium. Although this idea of plasmon-soliton has been the subject of numerous theoretical papers since the eighties [1–4], up to now, no experimental evidence had been revealed yet. In the present study, a proper structure (Fig. 1a) has been designed and fabricated allowing the first experimental demonstration of these hybrid nonlinear waves merging spatial solitons and SPP. To be …
Preparation and characterisation of optical and optoelectronic devices based in two-dimensional semiconductors
2020
In the Materials Science field, two-dimensional materials have gained the scientific community attention in recent years. The change and the appearance of novel properties when their thickness is reduced to nanometric scale has special interest for its fundamental properties study for, from this base, the design and its implementation in devices. The wide variety of materials with the possibility of being exfoliated at the two-dimensional level opens the field to different applications, from optoelectronic devices, detection and sensing, energy storage, catalysis, medical applications and quantum information technologies, among others. This thesis gathers results in both directions: a funda…
Multipactor radiation analysis within a waveguide region based on a frequency-domain representation of the dynamics of charged particles
2009
[EN] A technique for the accurate computation of the electromagnetic fields radiated by a charged particle moving within a parallel-plate waveguide is presented. Based on a transformation of the time-varying current density of the particle into a time-harmonic current density, this technique allows the evaluation of the radiated electromagnetic fields both in the frequency and time domains, as well as in the near- and far-field regions. For this purpose, several accelerated versions of the parallel-plate Green's function in the frequency domain have been considered. The theory has been successfully applied to the multipactor discharge occurring within a two metal-plates region. The proposed…
Electromagnetic wave propagation in non-homogeneous waveguides
2015
We investigate an electromagnetic waveguide, having several cylindrical ends. The waveguide is assumed to be empty and to have a perfectly conductive boundary. We study the electromagnetic field, excited in the waveguide in the presence of charges and currents. The field can be described as a solution of the stationary Maxwell system with conductive boundary conditions and “intrinsic” radiation conditions at infinity. We prove the problem to be well-posed. Electromagnetic waves propagation in the waveguide can be described by means of a scattering matrix. We introduce such a matrix for all values of the spectral parameter k in the waveguide continuous spectrum and study its properties. Moreove…
Enseñanza de las ciencias : revista de investigación y experiencias didácticas
2021
This research focuses on teacher training in the Master's Degree in Secondary Educa- tion Teaching. The teaching guides of the specialisations of Biology and Geology and Physics and Che- mistry of the Master's Degree were analysed in order to know to what extent Education for Sustaina- bility (EfS) is present. Collaborative teams of teachers were arranged so as to promote the acquisition of competences in Sustainability among the training goals and to encourage resources and procedures for their effective achievement. This paper includes contributions that try to promote attention to EfS in Secondary School teacher training. Esta investigación se enmarca en la formación del profesorado en e…
Terahertz polarization-division multiplexing within a four-wire waveguide
2022
We demonstrate a new metal-wire waveguide topology, namely a four-wire waveguide, which simultaneously acts as a broadband terahertz polarization-division multiplexer and as a novel platform to realize the independent manipulation of polarization-division multiplexed terahertz signals.
Terminoloģijas lietojums mobilo iekārtu lietošanas instrukcijās
2018
Maģistra darbā pētīts terminoloģijas lietojums mobilo iekārtu lietošanas instrukcijās. Darba mērķis ir izpētīt vienotas terminoloģijas pieejamību tehniskās nozares terminoloģijai, kura izmantota mobilo iekārtu lietošanas pamācībās. Pētījumā izmantotās metodes ir teorētisko materiālu (grāmatu un publikāciju) apskats un izmantotās terminoloģijas un tās tulkojumu analīze. Pētījuma rezultāti liecina, ka lielākajai daļai no atlasītajiem terminiem nav pieejams vienots tulkojums, vai termins darināts latviešu valodā, kas secīgi noved pie situācijas, kurā tulkotājs kļūst par valodnieku, kuram jādarina terminoloģiskās frāzes.
Phase-delayed laser diode array allows ultrasonic guided wave mode selection and tuning
2013
Selecting and tuning modes are useful in ultrasonic guided wave non-destructive testing (NDT) since certain modes at various center frequencies are sensitive to specific types of defects. Ideally one should be able to select both the mode and the center frequency of the launched waves. We demonstrated that an affordable laser diode array can selectively launch either the S0 or A0 ultrasonic wave mode at a chosen center frequency into a polymer plate. A fiber-coupled diode array (4 elements) illuminated a 2 mm thick acrylic plate. A predetermined time delay matching the selected mode and frequency was employed between the output of the elements. The generated ultrasound was detected by a 215…
Analytical results for 2-D non-rectilinear waveguides based on a Green's function
2008
We consider the problem of wave propagation for a 2-D rectilinear optical waveguide which presents some perturbation. We construct a mathematical framework to study such a problem and prove the existence of a solution for the case of small imperfections. Our results are based on the knowledge of a Green's function for the rectilinear case.