Ara es mostren els items 31-50 de 89

  • Metastability of dark snoidal-type waves in quadrayic nonlinear media 

    Kartashov, Yaroslav V.; Egorov, A A; Zelenina, A S; Vysloukh, Victor A.; Torner Sabata, Lluís (2003-11)
    Article
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    We report the existence and basic properties of dark snoidal-type waves self-sustained in quadratic nonlinear media. Using a stability analysis technique, we reveal that they are almost completely stable, or metastable, ...
  • Multicolor lattice solitons 

    Kartashov, Yaroslav V.; Torner Sabata, Lluís; Vysloukh, Victor A. (2004-05)
    Article
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    We report on the existence of multicolor solitons supported by periodic lattices made from quadratic nonlinear media. Such lattice solitons bridge the gap between continuous solitons in uniform media and discrete solitons ...
  • Multipole vector solitons in nonlocal nonlinear media 

    Kartashov, Yaroslav V.; Torner Sabata, Lluís; Vysloukh, Victor A.; Mihalache, Dumitru (2006-03)
    Article
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    We show that multipole solitons can be made stable via vectorial coupling in bulk nonlocal nonlinear media. Such vector solitons are composed of mutually incoherent nodeless and multipole components jointly inducing a ...
  • Multipole-mode solitons in Bessel optical lattices 

    Kartashov, Yaroslav V.; Carretero Gonzalez, R; Malomed, B A; Vysloukh, Victor A.; Torner Sabata, Lluís (2005-12)
    Article
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    We study basic properties of quiescent and rotating multipole-mode solitons supported by axially symmetric Bessel lattices in a medium with defocusing cubic nonlinearity. The solitons can be found in different rings of the ...
  • Nonlinear switching of low-index defect modes in photonic lattices 

    Ye, F; Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2008-08)
    Article
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    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
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  • 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
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    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
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    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
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    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
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    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 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
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    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 ...
  • Optical surface waves supported and controlled by thermal waves 

    Kartashov, Yaroslav V.; Vysloukh, Victor A.; Torner Sabata, Lluís (2008-02)
    Article
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    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
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    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 soliton steering in optical lattices 

    Kartashov, Yaroslav V.; Torner Sabata, Lluís; Vysloukh, Victor A. (2004-05)
    Article
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    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
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    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
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    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
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    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
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    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 ...