Ara es mostren els items 41-60 de 65

    • Resonant, broadband, and highly efficient optical frequency conversion in semiconductor nanowire gratings at visible and UV wavelengths 

      Escalora, M.; Trull Silvestre, José Francisco; Cojocaru, Crina; Vincenti, M. A.; Carletti, Luca; Ceglia, Domenico de; Akozbek, Neset; De Angelis, C. (2019-08-01)
      Article
      Accés restringit per política de l'editorial
      Using a hydrodynamic approach, we examine bulk- and surface-induced second- and third-harmonic generationfrom semiconductor nanowire gratings having a resonant nonlinearity in the absorption region. We demonstrateresonant, ...
    • Retrieving linear and nonlinear optical dispersions of matter: combined experiment-numerical ellipsometry in silicon, gold and indium tin oxide 

      Rodríguez Suñé, Laura; Trull Silvestre, José Francisco; Akozbek, Neset; Ceglia, Domenico de; Vincenti, M. A.; Scalora, Michael; Cojocaru, Crina (2021-09-17)
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      Accés obert
      We have presented a combined experimental and numerical method that can be used to predict complex nonlinear dispersion curves in almost any material, based exclusively on the experimental determination of harmonic generation ...
    • Second and third harmonic generation from gold nanolayers: experiment versus theory 

      Rodríguez Suñé, Laura; Trull Silvestre, José Francisco; Akozbek, Neset; Ceglia, Domenico de; Vincenti, M. A.; Scalora, Michael; Cojocaru, Crina (EPJ Web of Conferences, 2021)
      Text en actes de congrés
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      The use of semiconductors, metals, or ordinary dielectrics in the process of fabrication of nanodevices is at the front edge of nowadays technology, exploiting the properties of light propagation and localization at ...
    • Second and third harmonic generation in disordered quadratic nonlinear media: application to short-pulse characterization 

      Roppo, Vito; Wang, W.; Kalinowski, K.; Vilaseca Alavedra, Ramon; Trull Silvestre, José Francisco; Cojocaru, Crina; Staliunas, Kestutis; Krolikowski, Wieslaw; Kivshar, Yu. (2010)
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      We study parametric frequency conversion in quadratic nonlinear media with disordered ferroelectric domains. We demonstrate that disorder allows realizing broadband second- and third-harmonic generation via cascading of ...
    • Second harmonic generation from an ITO nanolayer: experiment versus theory 

      Rodríguez Suñé, Laura; Scalora, Michael; Johnson, Allan; Cojocaru, Crina; Akozbek, Neset; Coppens, Zachary; Pérez Salinas, Daniel; Wall, Simon; Trull Silvestre, José Francisco (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2020)
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      We report a comparative experimental and theoretical study of second harmonic generation from a 20nm-thick indium tin oxide nanolayer in the proximity of the epsilon-near-zero condition. We record the efficiency of the ...
    • Second-harmonic generation in disordered quadratic media: role of a ferroelectric domain structure 

      Roppo, Vito; Kalinowski, K.; Wang, W.; Cojocaru, Crina; Trull Silvestre, José Francisco; Vilaseca Alavedra, Ramon; Scalora, M.; Krolikowski, Wieslaw; Kivshar, Yu. (2010)
      Text en actes de congrés
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      We study theoretically the second harmonic generation in a nonlinear quadratic crystal with random distribution of ferroelectric domains. We show that the specific features of disordered domain structure greatly affect the ...
    • Second-harmonic generation in disordered quadratic media: role of a ferroelectric domain structure 

      Roppo, Vito; Kalinowski, K.; Wang, W.; Cojocaru, Crina; Trull Silvestre, José Francisco; Vilaseca Alavedra, Ramon; Scalora, M.; Krolikowski, Wieslaw; Kivshar, Yu. (2010)
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      Naturally grown ferroelectric crystals such as Strontium Barium Niobate (SBN) often exhibit an irregular multidomain structure with rod-like domains [1]. These disordered nonlinear quadratic crystals have attracted a ...
    • Signatures of light-beam spatial filtering in a three-dimensional photonic crystal 

      Maigyte, Lina; Gertus, T.; Peckus, Martynas; Trull Silvestre, José Francisco; Sirutkaitis, Valdas; Cojocaru, Crina; Staliunas, Kestutis (2010-08-13)
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      Accés obert
      We report experimental evidence of spatial filtering of light beams by three-dimensional, low-refraction-index-contrast photonic crystals. The photonic crystals were fabricated in a glass bulk, where the refraction index ...
    • Single-shot d-scan technique for ultrashort laser pulse characterization using transverse second-harmonic generation in random nonlinear crystals 

      Cojocaru, Crina; Trull Silvestre, José Francisco; Romero Muñiz, Rosa María; Sola Larrañaga, Iñigo Juan (2020-07-15)
      Article
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      We demonstrate a novel dispersion-scan (d-scan) scheme for single-shot temporal characterization of ultrashort laser pulses. The novelty of this method relies on the use of a highly dispersive crystal featuring antiparallel ...
    • Spatial filtering in broad area semiconductor laser using photonic crystal 

      Gawali, Sandeep Babu; Gailevicius, Darius; Purlys, Vytautas; Trull Silvestre, José Francisco; Cojocaru, Crina; Staliunas, Kestutis (2020)
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      In high power regimes, broad area semiconductor lasers usually suffer from poor beam quality due to their asymmetric beam divergence, large beam quality factor (M2) and from the absence of any intrinsic filtering mechanism ...
    • 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)
      Article
      Accés obert
      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 ...
    • Study of second and third harmonic generation from an indium tin oxide nanolayer: Influence of nonlocal effects and hot electrons 

      Rodríguez Suñé, Laura; Escalora, M.; Johnson, Allan; Cojocaru, Crina; Akozbek, Neset; Coppens, Zachary; Pérez Salinas, Daniel; Wall, Simon; Trull Silvestre, José Francisco (2020-01-03)
      Article
      Accés obert
      We report comparative experimental and theoretical studies of the second and third harmonic generation from a 20 nm-thick indium tin oxide layer in proximity of the epsilon-near-zero condition. Using a tunable optical ...
    • Surface and bulk harmonic generation in the opaque region of GaAs 

      Rodríguez Suñé, Laura; Trull Silvestre, José Francisco; Scalora, Michael; Cojocaru, Crina (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2019)
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      We demonstrate second and third harmonic generation from a GaAs substrate, well-bellow the absorption edge, in both transmission and reflection geometries. The pump is tuned at 1064 nm, in the transparency range, while the ...
    • Tailoring Cerenkov second-harmonic generation in bulk nonlinear photonic crystal 

      Sheng, Yan; Roppo, Vito; Kong, Qian; Kalinowski, K.; Wang, Qi; Cojocaru, Crina; Trull Silvestre, José Francisco; Krolikowski, W. (2011-07-01)
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      Accés obert
      We investigate theoretically the Čerenkov-type second-harmonic generation in two-dimensional bulk nonlinear photonic crystal with longitudinal modulation of the χ(2) nonlinearity. We show that in this scheme the Čerenkov ...
    • The effect of domain distribution on second harmonic generation in disordered nonlinear media 

      Roppo, Vito; Saltiel, Salomon M.; Wang, W.; Kalinowski, K.; Trull Silvestre, José Francisco; Cojocaru, Crina; Neshev, Dragomir N.; Krolikowski, Wieslaw; Vilaseca Alavedra, Ramon; Staliunas, Kestutis; Kivshar, Yu. (2009)
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      We study theoretically and experimentally the second harmonic generation in nonlinear crystals with random distribution of ferroelectric domains. We show that the specific features of disordered domain structure greatly ...
    • The role of the phase locking phenomenon in the second and third harmonics cavity localization 

      Roppo, Vito; Cojocaru, Crina; D'Agunaro, G.; Ranieri, F.; Raj, R.; Trull Silvestre, José Francisco; Vilaseca Alavedra, Ramon; Scalora, M. (2009)
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      We theoretically and experimentally study how the phase-locking mechanism changes effective dispersion of the medium at the harmonic frequencies making them become localized inside a opaque cavity designed to be resonant ...
    • Theoretical study of Cerenkov-type second-harmonic generation in periodically poled ferroelectric crystals 

      Sheng, Yan; Kong, Qian; Roppo, Vito; Kalinowski, K.; Wang, Qi; Cojocaru, Crina; Krolikowski, W. (2012-03)
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      Accés obert
      We study theoretically the Čerenkov-type second-harmonic generation by a Gaussian beam in quadratic nonlinear media with periodically reverted ferroelectric domains. In particular, we consider the role of fundamental ...
    • Three orders of magnitude enhancement of second and third harmonic generation in the visible and ultraviolet ranges from plasmonic gold nanogratings 

      Mukhopadhyay, Shroddha; Rodríguez Suñé, Laura; Cojocaru, Crina; Vincenti, M. A.; Anson Hallman, Kent; Leo, Giuseppe; Belchovski, Metodi; Ceglia, Domenico de; Scalora, Michael; Trull Silvestre, José Francisco (2023-04-07)
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      Accés obert
      We report experimental observations and numerical simulations of second and third harmonic generation from a gold nanograting, which exhibits a plasmonic resonance in the near infrared. The resonance is tunable, with a ...
    • Transverse cross-correlation scheme for pulse shape measurement in random nonlinear crystals 

      Cojocaru, Crina; Wang, Bingxia; Trull Silvestre, José Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2016)
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      We present a novel single-shot cross-correlation scheme based on the measurement of the transverse second harmonic generation (TSHG) in crystals with randomly distributed nonlinear ferroelectric domains. We implement it ...
    • Transverse single-shot cross-correlation scheme for laser pulse temporal measurement via planar second harmonic generation 

      Wang, Bingxia; Cojocaru, Crina; Krolikowski, Wieslaw; Yan Sheng, Yan Sheng; Trull Silvestre, José Francisco (2016-09-15)
      Article
      Accés obert
      We present a novel single-shot cross-correlation technique based on the analysis of the transversally emitted second harmonic generation in crystals with random distribution and size of anti-parallel nonlinear domains. We ...