Recent Submissions

  • Sharp acoustic vortex focusing by Fresnel-spiral zone plates 

    Jimenez, Noe; Romero García, Vicenç; Garcia Raffi, Luis Miguel; Staliunas, Kestutis (2018-05-14)
    Article
    Restricted access - publisher's policy
    We report the optimal focusing of acoustic vortex beams by using flat lenses based on a Fresnel- spiral diffraction grating. The flat lenses are designed by spiral-shaped Fresnel zone plates composed of one or several arms. ...
  • Self-induced Faraday instability laser 

    Perego, A.M.; Smirnov, Sergey V.; Staliunas, Kestutis; Churkin, D.V.; Wabnitz, Stefan (American Institute of Physics (AIP), 2018-05-22)
    Article
    Open Access
    We predict the onset of self-induced parametric or Faraday instabilities in a laser, spontaneously caused by the presence of pump depletion, which leads to a periodic gain landscape for light propagating in the cavity. As ...
  • Sub-threshold signal encoding in coupled FitzHugh-Nagumo neurons 

    Masoliver Vila, Maria; Masoller Alonso, Cristina (Nature, 2018-05-29)
    Article
    Open Access
    Despite intensive research, the mechanisms underlying the neural code remain poorly understood. Recent work has focused on the response of a single neuron to a weak, sub-threshold periodic signal. By simulating the stochastic ...
  • Experimental study of modulation waveforms for entraining the spikes emitted by a semiconductor laser with optical feedback 

    Tiana Alsina, Jordi; Quintero Quiroz, Carlos Alberto; Panozzo, M.; Torrent Serra, Maria del Carmen; Masoller Alonso, Cristina (2018-04-02)
    Article
    Open Access
    The entrainment phenomenon, by which an oscillator adjusts its natural rhythm to an external periodic signal, has been observed in many natural systems. Recently, attention has focused on which are the optimal conditions ...
  • A two dimensional KTiOPO4 photonic crystal grown using a macroporous silicon template 

    Peña Revellez, Alexandra; Finizio, Sergio Di; Todorov Trifonov, Trifon; Carvajal, Joan Josep; Aguiló Díaz, Magdalena; Pallarès Marzal, Josep; Rodríguez Martínez, Ángel; Alcubilla González, Ramón; Marsal Garví, Lluís Francesc; Diaz, Francesc; Martorell Pena, Jordi (2006-09)
    Article
    Restricted access - publisher's policy
    2D KTiOPO4 photonic crystals are fabricated using a silicon membrane of air holes as a template. Columns of KTiOPO4 are grown by liquid-phase epitaxy from a substrate into such air holes. The crystallographic orientation ...
  • Quantifying changes in spatial patterns of surface air temperature dynamics over several decades 

    Zappala, Dario; Barreiro, Marcelo; Masoller Alonso, Cristina (2018-04-18)
    Article
    Open Access
  • Comparative analysis of ferroelectric domain statistics via nonlinear diffraction in random nonlinear materials 

    Wang, Bin; Switowski, K; Cojocaru, Crina; Roppo, V; Sheng, Yan; Escalora, M.; Kisielewski, J.; Pawlak, D.; Vilaseca Alavedra, Ramon; Akhouayri, H.; Krolikowski, Wieslaw; Trull Silvestre, José Francisco (2018-01-22)
    Article
    Open Access
    We present an indirect, non-destructive optical method for domain statistic characterization in disordered nonlinear crystals having homogeneous refractive index and spatially random distribution of ferroelectric domains. ...
  • Directionality fields generated by a local Hilbert transform 

    Ahmed, W. W.; Herrero Simon, Ramon; Botey Cumella, Muriel; Hayran, Zeki; Kurt, Hamza; Staliunas, Kestutis (American Physical Society, 2018-03-15)
    Article
    Open Access
    We propose an approach based on a local Hilbert transform to design non-Hermitian potentials generating arbitrary vector fields of directionality, ¿p(¿r), with desired shapes and topologies. We derive a local Hilbert ...
  • Persistence and stochastic periodicity in the intensity dynamics of a fiber laser during the transition to optical turbulence 

    Carpi, Laura C.; Masoller Alonso, Cristina (2018-02-27)
    Article
    Open Access
    Many natural systems display transitions among different dynamical regimes, which are difficult to identify when the data are noisy and high dimensional. A technologically relevant example is a fiber laser, which can display ...
  • Collective excitability in a mesoscopic neuronal model of epileptic activity 

    Jedynak, Maciej; Pons Rivero, Antonio Javier; García Ojalvo, Jordi (2018-01-12)
    Article
    Open Access
    At the mesoscopic scale, the brain can be understood as a collection of interacting neuronal oscillators, but the extent to which its sustained activity is due to coupling among brain areas is still unclear. Herewe address ...
  • Generation of extreme pulses on demand in semiconductor lasers with optical injection 

    Tian, Jin; Chen, Siyu; Masoller Alonso, Cristina (2017-12-11)
    Article
    Open Access
    The generation of extreme intensity pulses in an optically injected semiconductor laser is studied numerically by using a well-known rate equation model. We show that step-up perturbations of the laser pump current can ...
  • Monolithic CIGS-Perovskite tandem cell for optimal light harvesting without current matching 

    Mantilla Perez, Paola; Correa Baena, Juan Pablo; Liu, Quan; Colodrero, Silvia; Toudert, Johann; Saliba, Michale; Hagfeldt, Anders; Martorell Pena, Jordi (2017-03-22)
    Article
    Open Access
    We present a novel monolithic architecture for optimal light harvesting in multijunction thin film solar cells. In the configuration we consider, formed by a perovskite (PVK) cell overlying a CIGS cell, the current extracted ...

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