Ara es mostren els items 92-111 de 128

    • Regularization of broad-area lasers by non-Hermitian potentials 

      Botey Cumella, Muriel; Ahmed Waseem, Waqas Waseem; Medina, Judith; Herrero Simon, Ramon; Wu, Ying; Staliunas, Kestutis (2019)
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      It was recently shown that arbitrary non-Hermitian optical potentials based on local Parity-Time (PT-) symmetry may control the flow of light, due to the asymmetric mode coupling. We propose periodic non-Hermitian potentials ...
    • Regularization of vertical-cavity surface-emitting laser emission by periodic non-Hermitian potentials 

      Ahmed Waseem, Waqas Waseem; Herrero Simon, Ramon; Botey Cumella, Muriel; Wu, Ying; Staliunas, Kestutis (2019-08-15)
      Article
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      We propose a novel physical mechanism based on periodicnon-Hermitian potentials to efficiently control the complexspatial dynamics of broad-area lasers, particularly in vertical-cavity surface-emitting lasers (VCSELs), ...
    • Restricted Hilbert transform for feasible light management 

      Botey Cumella, Muriel; Ahmed Waseem, Waqas Waseem; Herrero Simon, Ramon; Wu, Yina; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2021)
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      A feasible restricted Hilbert Transform (HT) is presented to solve the challenging practical realization of non-Hermitian systems, restricting the complex susceptibility within practical limits. Beyond closed-conservative ...
    • Restricted Hilbert Transform for Non-Hermitian Management of Fields 

      Waseem Ahmed, Waqas; Herrero Simon, Ramon; Botey Cumella, Muriel; Wu, Ying; Staliunas, Kestutis (2020-10-07)
      Article
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      Non-Hermitian systems exploiting the synergy between the properties of closed-conservative systems and open-dissipative (gain-loss) systems have recently become the playground to uncover unusual physical phenomena. Indeed, ...
    • Self-cleaning in non-Hermitian linear multimode fibers 

      Akhter, Mohammad Nayeem; Herrero Simon, Ramon; Staliunas, Kestutis; Botey Cumella, Muriel (Institute of Electrical and Electronics Engineers (IEEE), 2023)
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      We propose a self-cleaning mechanism in linear non-Hermitian graded index multimode fibers. The proposal is based a unidirectional coupling among transverse modes, induced by the introduction of a non-Hermitian potential, ...
    • Self-collimated beams in 2D complex periodic lattices from P- to PT-symmetry 

      Ahmed Waseem, Waqas Waseem; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (2017)
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      We analyze self-collimation in two-dimensional periodic complex lattices. We consider P-symmetric and PT-symmetric complex lattices with different geometries, where the periodic modulations of both refractive index and ...
    • Self-collimation in 2D Complex P- and PT-symmetric systems 

      Botey Cumella, Muriel; Ahmed Waseem, Waqas Waseem; Herrero Simon, Ramon; Staliunas, Kestutis (2017)
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      We predict the self-collimation phenomena (or equivalently, dynamical localization) in 2-dimensional P-symmetric and PT-symmetric complex potentials, with periodic modulations of both gain/loss and refractive index. ...
    • Self-collimation in PT -symmetric crystals 

      Ahmed Waseem, Waqas Waseem; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (AMER PHYSICAL SOC, 2017-05-10)
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      We predict the self-collimation phenomena (or equivalently, dynamical localization) in two-dimensional PT-symmetric complex potentials, where the complex modulation is considered in the transverse, longitudinal, or ...
    • Simulations and analysis of beam quality improvement in spatially modulated broad area edge-emitting devices 

      Radziunas, Mindaugas; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2014)
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      We simulate and analyze how beam quality improves while being amplified in edge emitting broad area semiconductor amplifiers with a periodic structuring of the electrical contacts, in both longitudinal and lateral directions. ...
    • Slow light enabled wavelength demultiplexing 

      Hayran, Zeki; Turduev, M.; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis; Kurt, H. (Institute of Electrical and Electronics Engineers (IEEE), 2016)
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      Photonic crystal waveguides supporting band gap guided modes hold great potential to tailor the group velocity of propagating light. We propose and explore different wavelength demultiplexer design approaches that ...
    • Sound directivity by PT-symmetric acoustic dipoles 

      Magariyachi, Tetsu; Arias Casals, Helena; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2021)
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      The new physics of open-dissipative, non-Hermitian systems have become a fruitful playground to uncover novel physical phenomena, even in exotic or counterintuitive ways, especially in optics and, more recently, also in ...
    • Spatial filtering in edge-emitting lasers by intracavity chirped photonic crystals 

      Gawali, Sandeep Babu; Medina Pardell, Judith; Gailevicius, D.; Purlys, Vytautas; Garre Werner, Guillermo; Cojocaru, Crina; Trull Silvestre, José Francisco; Botey Cumella, Muriel; Herrero Simon, Ramon; Montiel Ponsoda, Joan; Staliunas, Kestutis (2020-10-01)
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      In this work, we report an experimental and numerical study of the intracavity spatial filtering in edge-emitting lasers using a chirped photonic crystal (PhC) as the filtering element in the near-field domain. We provide ...
    • Spatial noise reduction in broad area semiconductors 

      Herrero Simon, Ramon; Botey Cumella, Muriel; Pradeep Kumar, Nikhil; Staliunas, Kestutis (IEEE, 2012)
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    • Spatiotemporal stabilization of PT-symmetric BAS lasers 

      Medina Pardell, Judith; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2020)
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      We propose a compact solution to spatially regularize and temporally stabilize edge emitting (broad area) semiconductor lasers. The scheme relays on the local asymmetries generated by a non-Hermitian potential with a central ...
    • 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)
      Report de recerca
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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 ...
    • Stabilisation of spatially periodic states by non-Hermitian potentials 

      Benadouda Ivars, Salim; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (2023-03)
      Article
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      We uncover new families of stable periodic solutions by the introduction of non-Hermitian potentials in the universal complex Ginzburg–Landau equation. We perform a comprehensive analysis on the dynamics and stability of ...
    • Stabilization of Broad Area Semiconductor Amplifiers and Lasers by Double Modulation of Pump and Refractive Index 

      Ahmed Waseem, Waqas Waseem; Kumar, Shubham; Medina Pardell, Judith; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (Institute of Electrical and Electronics Engineers (IEEE), 2018)
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      Broad Area Semiconductor Amplifiers and Lasers display instability of the homogeneous state typically related with self-focusing nonlinearities, inducing multi-transverse mode operation and filamentation that deteriorates ...
    • Stabilization of Broad Area Semiconductor Laser Sources 

      Medina Pardell, Judith; Ahmed Waseem, Waqas Waseem; Kumar, Shubham; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (Institute of Electrical and Electronics Engineers (IEEE), 2018)
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      We numerically proof the stabilization of broad area semiconductor laser sources by introducing simultaneous in-phase two-dimensional modulations on the refractive index and on the pump (gain). We also examine the interplay ...
    • Stabilization of broad area semiconductor lasers 

      Kumar, Shubham; Ahmed Waseem, Waqas Waseem; Herrero Simon, Ramon; Botey Cumella, Muriel; Staliunas, Kestutis (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2018)
      Text en actes de congrés
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      Broad Area Semiconductor edge-emitting lasers typically display self-focusing nonlinearity due to the refractive index dependence on the population inversion. It induces the homogeneous solution instability, multi-transverse ...
    • Stabilization of broad-area semiconductor laser sources by simultaneous index and pump modulations 

      Waseem Ahmed, Waqas; Kumar, Shubham; Medina Pardell, Judith; Botey Cumella, Muriel; Herrero Simon, Ramon; Staliunas, Kestutis (2018-06-01)
      Article
      Accés obert
      We show that the emission of broad-area semiconductor amplifiers and lasers can be efficiently stabilized by introducing two-dimensional periodic modulations simultaneously on both the refractive index and the pump (gain–loss) ...