Enviaments recents

  • Extremely narrow, sharp-peaked resonances at the edge of the continuum 

    Lukošiunas, Ignas; Grineviciute, Lina; Nikitina, Julianija; Gailevicius, Darius; Staliunas, Kestutis (2022-11-03)
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    We report a critical narrowing of resonances of a driven potential well, when their eigenfrequencies approach the edge of the continuum. The resonances also obtain unusual sharp-peak shapes at the continuum boundary. The ...
  • Non-Hermitian mode cleaning in periodically modulated multimode fibers 

    Akhter, Mohammad Nayeem; Benadouda Ivars, Salim; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (2022-11-23)
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    We show that the simultaneous modulation of the propagation constant and of the gain/loss coefficient along the multimode fibers results in unidirectional coupling among the modes, which, depending on the modulation ...
  • Non-Hermitian arrangement for stable semiconductor laser arrays 

    Botey Cumella, Muriel; Herrero Simon, Ramon; Medina Pardell, Judith; Staliunas, Kestutis (2021-06-16)
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    We propose and explore a physical mechanism for the stabilization of the complex spatiotemporal dynamics in arrays (bars) of broad area laser diodes taking advantage of the symmetry breaking in non-Hermitian potentials. ...
  • Nonspreading Light Pulses in Photonic Crystals 

    Staliunas, Kestutis; Serrat Jurado, Carles; Herrero Simon, Ramon; Cojocaru, Crina; Trull Silvestre, José Francisco (2005-05)
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    We investigate propagation of light pulses in photonic crystals in the vicinity of the zero-diffraction point. We show that Gaussian pulses due to nonzero width of their spectrum spread weakly in space and time during the ...
  • About the oscillatory possibilities of the dynamical systems 

    Herrero Simon, Ramon; Pi Vila, Francesc; Rius, J; Orriols Tubella, Gaspar (2009-11)
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    This paper may be ultimately described as an attempt to make feasible the evolutionary emergence of novelty in a supposedly deterministic world whose behavior is associated with that of the mathematical dynamical systems. ...
  • Unphysical source of dynamic order for the natural world 

    Herrero Simon, Ramon; Farjas Silva, Jordi; Pi Vila, Francesc; Orriols Tubella, Gaspar (2016-10)
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    The well-defined but intricate course of time evolution exhibited by many naturally occurring phenomena suggests some source of dynamic order sustaining it. In spite of its obviousness as a problem, it has remained absent ...
  • Spatiotemporal stabilization proof of concept of Broad Area Semiconductor laser sources 

    Medina Pardell, Judith; Ahmed Waseem, Waqas Waseem; Kumar, Shubham; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (2018-02)
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    We provide a numerical proof of concept of a stabilization mechanism for BAS laser sources. The scheme is based on the simultaneous introduction of in-phase two-dimensional modulations on the refractive index and pump ...
  • Subdiffraction and spatial filtering due to periodic spatial modulation of the gain/loss profile 

    Staliunas, Kestutis; Herrero Simon, Ramon; Vilaseca Alavedra, Ramon (2018-11)
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    We investigate light propagation through materials with periodically modulated gain/loss profile in both transverse and longitudinal directions, i.e. in material with two-dimensional modulation in space. We predict effects ...
  • Designable Dynamical Systems for the Generalized Landau Scenario and the Nonlinear Complexification of Periodic Orbits 

    Herrero Simon, Ramon; Farjas Silva, Jordi; Pi Vila, Francesc; Orriols Tubella, Gaspar (2021-02)
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    We have found a way for penetrating the space of the dynamical systems towards systems of arbitrary dimension exhibiting the nonlinear mixing of a large number of oscillation modes through which extraordinarily complex ...
  • Genetic optimization Invents non-Hermitian potentials for Asymmetric Reflectivity 

    Ahmed Waseem, Waqas Waseem; Herrero Simon, Ramon; Botey Cumella, Muriel; Wu, Ying; Staliunas, Kestutis (2020-08)
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    We propose a general design strategy based on genetic optimization to realize asymmetric reflectivity in periodic and non-periodic planar structures containing dielectric and gain-loss layers. By means of an optimization ...
  • Study of the charge profile of thermally poled electrets 

    Parsa, Seyedeh Elaheh; Trull Silvestre, José Francisco; Colom Fajula, Xavier; Sellarès González, Jordi (2016-02-17)
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    The charge profile of thermally poled electrets has been studied using two different methods, laser induced pressure pulse (LIPP) and pulsed electroacoustic (PEA), to gain insight into the mechanisms that are activated and ...