Ara es mostren els items 62-81 de 128

    • Light control by Non-Hermitian modulation in multimode fiber 

      Akhter, Mohammad Nayeem; Benadouda Ivars, Salim; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (META Conference, 2022)
      Text en actes de congrés
      Accés obert
      We show that a non-Hermitian modulation of the potential along the nonlinear multimode fibers controls dynamics of propagating radiation. Specifically we consider simultaneous modulation of the refraction index and gain/loss ...
    • Light control by scattering cancellation in ordered and disordered non-Hermitian media, direct and inverse design 

      Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2023)
      Text en actes de congrés
      Accés obert
      Non-Hermitian Physics has emerged as a fertile ground for a smart control of waves. Here, we present direct and inverse-design strategies to achieve ‘on demand’ dynamical manipulation of light by non-Hermitian potentials. ...
    • Light in materials with periodic gain-loss modulation on a wavelength scale 

      Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (2010-07-22)
      Article
      Accés restringit per política de l'editorial
    • Locally parity-time-symmetric and globally parity-symmetric systems 

      Ahmed Waseem, Waqas Waseem; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (2016-11-11)
      Article
      Accés obert
      We introduce a class of systems holding parity-time (PT) symmetry locally, whereas being globally P symmetric. The potential, U = U(vertical bar r vertical bar), fulfills PT symmetry with respect to periodically distributed ...
    • Management of Light Patterns Based on Local Hilbert Transform 

      Staliunas, Kestutis; Ahmed, W.; Botey Cumella, Muriel; Herrero Simon, Ramon; Hayran, Zeki; Kurt, H. (2018)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      We propose a new approach of optical field management based on a local Hilbert transform, where the non-Hermitian potentials generating arbitrary vector fields of directionality p(\vec r), with desired shapes and topologies ...
    • Managing spatial diffraction through a periodic loss modulation 

      Botey Cumella, Muriel; Pradeep Kumar, Nikhil; Herrero Simon, Ramon; Maigyte, Lina; Staliunas, Kestutis (2014)
      Comunicació de congrés
      Accés obert
      We show that periodic distributions of gain or losses on the wavelength scale allow managing spatial diffraction of light beams, with no index contrast. It has been recently predicted that such artificial periodic structures, ...
    • Meta-mirrors with transverse invariance for beam shaping 

      Cheng, Yu-Chieh; Wang, Pei-Yu; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2019)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      The paper demonstrates spatial filtering in reflection based on meta-mirrors, composed of periodic subwavelength gratings. The periodic modulation of the refraction index on the sub-micron scale exhibits optical beam shaping ...
    • Mode-cleaning in antisymmetrically modulated non-Hermitian waveguides 

      Akhter, Mohammad Nayeem; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (2024-01-12)
      Article
      Accés obert
      We demonstrate all-optical spatial mode-cleaning in non-Hermitian waveguides. The effect is accounted by a unidirectional coupling among the modes resulting from a simultaneous modulation of the refractive index and the ...
    • Near surface geophysical analysis of the Navamuño depression (Sierra de Béjar, Iberian Central System): geometry, sedimentary infill and genetic implications of tectonic and glacial footprint 

      Carrasco González, Rosa M.; Turu Michels, Valentí; Pedraza Gilsanz, Javier de; Herrero Simon, Ramon (2018-08-15)
      Article
      Accés obert
      The geometric and genetic characterization of the Navamuño depression peatland system (Iberian Central System) is presented here using results from a geophysical survey. This depression is a ~30¿ha pseudo-endorheic flat ...
    • Negative diffraction by a periodically modulated loss 

      Botey Cumella, Muriel; Pradeep Kumar, Nikhil; Herrero Simon, Ramon; Maigyte, Lina; Picó, Ruben; Staliunas, Kestutis (Institute of Electrical and Electronics Engineers (IEEE), 2013)
      Comunicació de congrés
      Accés restringit per política de l'editorial
    • Non-Hermitian arrangement for stable semiconductor laser arrays 

      Botey Cumella, Muriel; Herrero Simon, Ramon; Medina Pardell, Judith; Staliunas, Kestutis (2021-06-16)
      Report de recerca
      Accés obert
      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. ...
    • Non-Hermitian arrangement for stable semiconductor laser arrays 

      Medina Pardell, Judith; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (2021-07-19)
      Article
      Accés obert
      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. ...
    • Non-Hermitian broad aperture semiconductor lasers based on PT-symmetry 

      Botey Cumella, Muriel; Waseem Ahmed, Waqas; Medina Pardell, Judith; Herrero Simon, Ramon; Staliunas, Kestutis (2019)
      Text en actes de congrés
      Accés obert
      In this paper we propose a novel configuration to regularize the complex spatiotemporal dynamics of broad area lasers into bright light beam. It has recently been shown that arbitrary non-Hermitian optical potentials based ...
    • Non-Hermitian control of optical turbulence in systems with fractional dispersion 

      Benadouda Ivars, Salim; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (Elsevier, 2022-12-01)
      Article
      Accés obert
      We show an efficient mechanism to control optical turbulence in systems with different dispersion laws, including parabolic, sub-diffractive, hyper-diffractive or general fractional dispersion. The method is based on the ...
    • Non-Hermitian coupled semiconductor laser array 

      Herrero Simon, Ramon; Medina Pardell, Judith; Botey Cumella, Muriel; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2022)
      Text en actes de congrés
      Accés obert
      We propose and explore a stabilization mechanism of a semiconductor laser array based on asymmetric coupling between neighboring lasers. The stabilization scheme takes advantage of the symmetry breaking of non-Hermitian ...
    • Non-Hermitian light control in periodically modulated multimode fibers 

      Akhter, Mohammad Nayeem; Benadouda Ivars, Salim; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (2023)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      We propose a new light management mechanism in graded index (GRIN) multimode fibers (MMFs) that allow to control the spectral mode distribution of the propagated beam. The effect is achieved through longitudinal non-Hermitian ...
    • Non-Hermitian Light Management Based on Local Hilbert Transform 

      Staliunas, Kestutis; Waseem Ahmed, Waqas; Botey Cumella, Muriel; Herrero Simon, Ramon (Institute of Electrical and Electronics Engineers (IEEE), 2019)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Light patterns; Metamaterials; Non-Hermitian optics; Microlasers
    • 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)
      Report de recerca
      Accés obert
      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 modulations for stabilization of VCSEL, EEL and EEL arrays 

      Herrero Simon, Ramon; Benadouda Ivars, Salim; Botey Cumella, Muriel; Staliunas, Kestutis (2023)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      Semiconductor lasers and laser arrays emit temporally unstable and low spatial quality beams associated to intrinsic dynamical spatiotemporal instabilities. W e propose the simultaneous modulations of refractive index and ...
    • Nondiffractive-nondiffusive beams in complex crystals 

      Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (2014-06-16)
      Article
      Accés obert
      The study of spatial dispersion of two-dimensional complex crystals, with periodic modulations of both gain-loss and the refractive index, reveals simultaneous nondiffractive-nondiffusive light propagation. Narrow light ...