Now showing items 21-40 of 432

  • Bound states in the continuum in a two-dimensional PT - symmetric system 

    Kartashov, Yaroslav V.; Milian, Carles; Konotop, Vladimir V; Torner Sabata, Lluís (2018-02-01)
    Article
    Open Access
    We address a 2D parity-time (¿¿)-symmetric structure built as a chain of waveguides, where all waveguides except for the central one are conservative, while the central one is divided into two halves with gain and losses. ...
  • Bound states in the continuum in spin-orbit-coupled atomic systems 

    Kartashov, Yaroslav V.; Konotop, Vladimir V; Torner Sabata, Lluís (2017-09-14)
    Article
    Restricted access - publisher's policy
    We show that the interplay between spin-orbit coupling and Zeeman splitting in atomic systems can lead to the existence of bound states in the continuum (BICs) supported by trapping potentials. Such states have energies ...
  • Bragg guiding of domainlike nonlinear modes and kink arrays in lower-index core structures 

    Ye, F; Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2008-06)
    Article
    Restricted access - publisher's policy
    We introduce a novel class of stable nonlinear modes trapped in a lower-index film core sandwiched between two optical lattices, or in the cylindrical core of a radial lattice, imprinted in defocusing media. Such a family ...
  • Bragg-type soliton mirror 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2006-02)
    Article
    Restricted access - publisher's policy
    We study soliton reflection/transmission at the interface between uniform medium and the optical lattice with focusing Kerr nonlinearity. We reveal that such interfaces afford rich new opportunities for controlling the ...
  • Bright solitons from defocusing nonlinearities 

    Borovkova, Olga V.; Kartashov, Yaroslav; Torner Sabata, Lluís; Malomed, Boris A. (2011-09-19)
    Article
    Restricted access - publisher's policy
    We report that defocusing cubic media with spatially inhomogeneous nonlinearity, whose strength increases rapidly enough toward the periphery, can support stable bright localized modes. Such nonlinearity landscapes give ...
  • Broadband light generation by noncollinear parametric down-conversion 

    Carrasco, S; Nars, M B; Sergienko, A; Saleh, B E A; Teich, M C; Pérez Torres, Juan; Torner Sabata, Lluís (2006-01)
    Article
    Restricted access - publisher's policy
    Broadband light generation is demonstrated by noncollinear spontaneous parametric downconversion with a cw pump laser. By use of a suitable noncollinear phase-matching geometry and a tightly focused pump beam, downconverted ...
  • Brownian soliton motion 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2008-05)
    Article
    Restricted access - publisher's policy
    We reveal fundamental analogies between soliton dynamics in light-induced random photonic lattices and Brownian motion of particles. In particular, we discover that the average squared soliton displacement increases linearly ...
  • Cavity solitons in a microring dimer with gain and loss 

    Milián, Carles; Kartashov, Yaroslav V.; Skryabin, Dmitry V.; Torner Sabata, Lluís (2018-02-20)
    Article
    Open Access
    We address a pair of vertically coupled microring resonators with gain and loss pumped by a single-frequency field. Coupling between microrings results in a twofold splitting of the single microring resonance that increases ...
  • Characterisation of the Hamamatsu photomultipliers for the KM3NeT Neutrino Telescope 

    Aiello, S; Ameli, F; André, Michel; Anghinolfi, Marco; Anton, G.; Ardid Ramírez, Miguel; Avgitas, T.; Bertin, V.; Bormuth, R.; Bouwhuis, M.C.; Puricelli, Stefano; Cherubini, Silvio; Coniglione, R.; Mannheim, Karl; Morganti, Michele; Pellegrino, Carlo; Piattelli, P.; Real, Del; Santangelo, A; Sharma, Aniruddh; Trovato, A.; Zaborov, D.; Zúñiga Román, Juan (2018-05-01)
    Article
    Open Access
    The Hamamatsu R12199-02 3-inch photomultiplier tube is the photodetector chosen for the first phase of the KM3NeT neutrino telescope. About 7000 photomultipliers have been characterised for dark count rate, timing spread ...
  • Characterization of dielectric spheres by spiral imaging 

    Petrov, Dimitri; Rahuel, Nicolás; Molina Terriza, Gabriel; Torner Sabata, Lluís (2012)
    Article
    Open Access
    We study the spiral spectra scattered off transparent dielectric spheres when probed by different Laguerre–Gaussian light beams, carrying nested topological wavefront dislocations. We show that such scattering data may ...
  • Classical and quantum applications of optical four wave mixing in an integrated silicon nitride platform 

    Triginer Garcés, Gil (Universitat Politècnica de Catalunya, 2014-12-19)
    Master thesis (pre-Bologna period)
    Open Access
    Covenantee:  University of Colorado Boulder
    [ANGLÈS] Integrated photonics provide a very versatile platform for nonlinear optics experiments, due to the tight field confinement that high index contrast structures offer and their great degree of tunability. Two ...
  • Closed-loop control of magnetic fields for atomic physics experiments 

    Luan, Jie (Universitat Politècnica de Catalunya, 2017-09-08)
    Master thesis
    Open Access
    This project explores the control of magnetic fields through active feedback, ultimately bringing the magnetic field noise level below the required threshold, for one single axis. An absolute stability of less than 400 uG ...
  • Clusters of cavity solitons bounded by conical radiation 

    Milián, Carles; Kartashov, Yaroslav V.; Skryabin, Dmitry V.; Torner Sabata, Lluís (American Institute of Physics (AIP), 2018-09-06)
    Article
    Open Access
    We introduce a new class of self-sustained states, which may exist as single solitons or form multisoliton clusters, in driven passive cylindrical microresonators. Remarkably, such states are stabilized by the radiation ...
  • Cnoidal wave patterns in quadratic nonlinear media 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2003-07)
    Article
    Restricted access - publisher's policy
    We report the existence of whole families of stationary cnoidal, periodic wave patterns in quadratic nonlinear media. We study the main physical features of the multicolored light patterns, including their shape, contrast, ...
  • Complex soliton-like pattern generation in potassium niobate due to noisy, high intensity, input beams 

    Jankovic, L; Polyakov, S; Stegeman, G; Carrasco Rodríguez, Sílvia; Torner Sabata, Lluís; Bosshard, Ch; Gunter, P (2003-09)
    Article
    Restricted access - publisher's policy
    We report the generation of complex soliton-like patterns in non-critically-phase-matched potassium niobate which occur in random spatial patterns from shot-to-shot. Up to five spots have been generated at input intensities ...
  • Composite vortex-ring solitons in Bessel photonic lattices 

    Kartashov, Yaroslav V.; Torner Sabata, Lluís; Vysloukh, Victor A. (2005-07)
    Article
    Restricted access - publisher's policy
    We reveal the existence of dynamically stable, composite topological solitons in Bessel photonic lattices imprinted in focusing Kerr-type nonlinear media. The new stable, composite solitons are made of a vortex ring with ...
  • Conformal transformation of Dyakonov surface waves into bound states of cylindrical metamaterials 

    Kajorndejnukul, Veerachart; Artigas García, David; Torner Sabata, Lluís (American Physical Society (APS), 2019-11-05)
    Article
    Open Access
    We put forward the use of transformation optics to map surface waves that exist as one-dimensional modes supported by anisotropic structures into bound states in two-dimensional geometries. Specifically, we show the conformal ...
  • Conmutacion totalmente optica de ondas guiadas en medios virefring. 

    Santos Blanco, M. Concepción; Pérez Torres, Juan; Torner Sabata, Lluís (1993)
    Conference report
    Open Access
    A new kind of tunable all-optical guided-wave thresholding device using waveguides consisting of both birefringent linear media and isotropic nonlinear media is discussed. The behavior of the lower threshold with a suitable ...
  • Continuous-wave self-pumped optical parametric oscillator based on Yb3+-doped bulk periodically-poled LiNbO3 (Mg0) 

    Capmany, J; Callejo, D; Bermúdez, V; Diéguez, E; Artigas García, David; Torner Sabata, Lluís (2001-05-15)
    Article
    Restricted access - publisher's policy
    We present experimental evidence of continuous-wave self-pumped parametric oscillation in Yb3+-doped periodically poled lithium niobate co-doped with MgO. A single bulk crystal of periodically poled lithium niobate containing ...
  • Controllable patterns of parametric solitons 

    Minardi, S; Molina Terriza, Gabriel; Bramati, A; Ditrapani, P; Torner Sabata, Lluís; Pérez Torres, Juan; Petrov, D V; Soto-Crespo, J M (2001-12)
    Article
    Restricted access - publisher's policy