Ara es mostren els items 40-59 de 108

  • Nonlinear switching of low-index defect modes in photonic lattices 

    Ye, F; Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2008-08)
    Article
    Accés restringit per política de l'editorial
    We address nonlinear signal switching between two low-index defect channels induced in periodic optical lattices. In contrast to conventional directional couplers, where the guiding mechanism is total internal reflection ...
  • Nonlinear Tamm states in periodic photonic structures 

    Rosberg, C R; Neshev, D N; Kartashov, Yaroslav V.; Vicencio, R A; Krolikowski, W; Molina, M I; Mitchell, A; Vysloukh, Victor A.; Torner Sabata, Lluís; Kivshar, Y S (2006-12)
    Article
    Accés restringit per política de l'editorial
  • Nonlinearity-induced broadening of resonances in dynamically modulated couplers 

    Szameit, Alexander; Kartashov, Yaroslav V.; Heinrich, Matthias; Dreisow, Felix; Keil, R; Nolte, Stefan; Tunnermann, A; Vysloukh, Victor A.; Lederer, F; Torner Sabata, Lluís (2009-01)
    Article
    Accés restringit per política de l'editorial
    We report the observation of nonlinearity-induced broadening of resonances in dynamically modulated directional couplers. When the refractive index of the guiding channels in the coupler is harmonically modulated along the ...
  • Observation of asymmetric solitons in waveguide arrays with refractive index gradient 

    Weimann, Steffen; Kartashov, Yaroslav V.; Vysloukh, Victor A.; Szameit, Alexander; Torner Sabata, Lluís (2014-06-15)
    Article
    Accés restringit per política de l'editorial
    We study light propagation in waveguide arrays made in Kerr nonlinear media with a transverse refractive index gradient, and we find that the presence of the refractive index gradient leads to the appearance of a number ...
  • Observation of surface solitons in chirped waveguide arrays 

    Szameit, Alexander; Kartashov, Yaroslav V.; Dreisow, Felix; Heinrich, Matthias; Pertsch, T; Nolte, Stefan; Tünnermann, A; Vysloukh, Victor A.; Torner Sabata, Lluís (2008-05)
    Article
    Accés restringit per política de l'editorial
    We report the observation of surface solitons in chirped semi-infinite waveguide arrays whose waveguides exhibit exponentially decreasing refractive indices. We show that the power threshold for surface wave formation ...
  • Observation of the gradual transition from one-dimensional to two-dimensional Anderson localization 

    Naether, U.; Kartashov, Yaroslav; Vysloukh, Victor A.; Nolte, S.; Tünnermann, A.; Torner Sabata, Lluís; Szameit, A. (2012-02-15)
    Article
    Accés restringit per política de l'editorial
    We study the gradual transition from one-dimensional to two-dimensional Anderson localization upon transformation of the di-mensionality of disordered waveguide arrays. An effective transition from one- to two-dimensional ...
  • Observation of two-dimensional coherent surface vector lattice solitons 

    Heinrich, Matthias; Kartashov, Yaroslav V.; Szameit, Alexander; Dreisow, Felix; Keil, R; Nolte, Stefan; Tunnermann, A; Vysloukh, Victor A.; Torner Sabata, Lluís (2009-01)
    Article
    Accés restringit per política de l'editorial
    We report, to the best of our knowledge, the first experimental observation of vector surface solitons, which form at the edge and in the corner of two-dimensional laser-written waveguide arrays. These elliptically polarized ...
  • Observation of two-dimensional defect surface solitons 

    Szameit, Alexander; Kartashov, Yaroslav V.; Heinrich, Matthias; Dreisow, Felix; Pertsch, T; Nolte, Stefan; Tunnermann, A; Lederer, F; Vysloukh, Victor A.; Torner Sabata, Lluís (2009-03)
    Article
    Accés restringit per política de l'editorial
    We report on the experimental observation of two-dimensional solitons located in defect channels at the surface of a hexagonal waveguide array. The threshold power for the excitation of solitons existing owing to total ...
  • Observation of two-dimensional lattice interface solitons 

    Szameit, Alexander; Kartashov, Yaroslav V.; Dreisow, Felix; Heinrich, Matthias; Vysloukh, Victor A.; Pertsch, T; Nolte, Stefan; Tunnermann, A; Lederer, F; Torner Sabata, Lluís (2008-04)
    Article
    Accés restringit per política de l'editorial
    We report on the experimental observation of two-dimensional solitons at the interface between square and hexagonal waveguide arrays. In addition to the different symmetries of the lattices, the influence of a varying ...
  • Observation of two-dimensional superlattice solitons 

    Heinrich, Matthias; Kartashov, Yaroslav; Ramírez, L. P. R.; Szameit, Alexander; Dreisow, Felix; Keil, R; Nolte, Stefan; Tünnermann, Andreas; Vysloukh, Victor A.; Torner Sabata, Lluís (2009-12)
    Article
    Accés restringit per política de l'editorial
    We observe experimentally two-dimensional solitons in superlattices comprising alternating deep and shallow waveguides fabricated via the femtosecond-laser direct writing technique. We find that the symmetry of linear ...
  • Optical surface waves supported and controlled by thermal waves 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2008-02)
    Article
    Accés restringit per política de l'editorial
    We address the formation of optical surface waves at the very edge of semiconductor materials illuminated by modulated light beams that generate thermal waves rapidly fading in the bulk material. We find families of ...
  • Oscillations of two-dimensional solitons in harmonic and Bessel optical lattices 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2005-03)
    Article
    Accés restringit per política de l'editorial
    We consider parametric amplification of two-dimensional spatial soliton oscillations in longitudinally modulated harmonic and Bessel lattices in Kerr-type saturable medium. We show that soliton center oscillations along ...
  • Parametric amplification of random lattice soliton swinging 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2009-05)
    Article
    Accés restringit per política de l'editorial
    We consider the propagation of solitons in media with an imprinted transverse periodic or parabolic refractive index modulation when the modulation depth fluctuates slightly along the propagation direction. We find that, ...
  • Parametric amplification of soliton steering in optical lattices 

    Kartashov, Yaroslav V.; Torner Sabata, Lluís; Vysloukh, Victor A. (2004-05)
    Article
    Accés restringit per política de l'editorial
    We report on the effect of parametric amplification of spatial soliton swinging in Kerr-type nonlinear media with longitudinal and transverse periodic modulation of the linear refractive index. The parameter areas are found ...
  • Power-dependent shaping of vortex solitons in optical lattices with spatially modulated nonlinearrefractive index 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2008-10)
    Article
    Accés restringit per política de l'editorial
    We address vortex solitons supported by optical lattices featuring modulation of both the linear and nonlinear refractive indices. We find that when the modulation is out of phase the competition between both effects results ...
  • Propagation of solitons in thermal media with periodic nonlinearity 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2008-08)
    Article
    Accés restringit per política de l'editorial
    We address the existence and properties of solitons in layered thermal media made of alternating focusing and defocusing layers. Such structures support robust bright solitons even if the averaged nonlinearity is defocusing. ...
  • Reconfigurable directional couplers and junctions optically induced by nondiffracting Bessel beams 

    Xu, Zhiyong; Kartashov, Yaroslav V.; Torner Sabata, Lluís; Vysloukh, Victor A. (2005-05)
    Article
    Accés restringit per política de l'editorial
    We put forward the concept of reconfigurable structures optically induced by mutually incoherent nondiffracting Bessel beams in Kerr-type nonlinear media. We address collinear couplers and X junctions and show how one can ...
  • Resonant Bloch-wave beatings 

    Kartashov, Yaroslav; Vysloukh, Victor A.; Torner Sabata, Lluís (2014-07-01)
    Article
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    We introduce Bloch-wave beatings in arrays of multimode periodically bent waveguides with a transverse refractive index gradient. The new phenomenon manifests itself in the periodic drastic increase of the amplitude of the ...
  • Resonant mode conversion in the waveguides with unbroken and broken PT symmetry 

    Vysloukh, Victor A.; Kartashov, Yaroslav (2014-10-15)
    Article
    Accés obert
    We study resonant mode conversion in parity time (PT)-symmetric multimode waveguides, where symmetry breaking manifests itself in the sequential destabilization (i.e., the appearance of complex eigenvalues) of the pairs ...
  • Resonant mode oscillations in modulated waveguiding structures 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2007-12)
    Article
    Accés restringit per política de l'editorial
    We put forward the concept of resonant, Rabi-like oscillatons and adiabatic transitions between confined light modes in properly modulated multimode waveguides. The phenomenon is shown to take place in both the linear and ...