Browsing by Author "Cojocaru, Crina"Més informacióMés informació

Now showing items 21-38 of 38

  • Observation of azimuthal modulation instability and formation of patterns of optical solitons in a quadratic nonlinear crystal 

    Petrov, Dimitri; Torner Sabata, Lluís; Martorell Pena, Jordi; Vilaseca Alavedra, Ramon; Pérez Torres, Juan; Cojocaru, Crina (1998-09)
    Article
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    We report what is believed to be the first experimental demonstration of the azimuthal self-breaking of intense beams containing a vortex phase dislocation into sets of optical spatial solitons in a quadratic nonlinear ...

  • Phase locked second harmonic etalon localization 

    Roppo, Vito; D'Aguanno, G.; Cojocaru, Crina; Raineri, F.; Trull Silvestre, José Francisco; Vilaseca Alavedra, Ramon; Raj, R; Scalora, M. (2009)
    Conference report
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    During the last decades a phase locking phenomenon has been observed for second harmonic (SH) generation but only recently it was recognized as such in systematic studies. The general solution of the SHG from a linear/nonlinear ...

  • Phononic crystal device as a self-collimator for laser induced ultrasound 

    Mohamed Selim, Hossameldin; Pico Vila, Rubén; Trull Silvestre, José Francisco; Delgado Prieto, Miquel; Cojocaru, Crina (Sociedad Española de Acústica (SEA), 2018)
    Conference report
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    Laser generated ultrasound has gained interest as an alternative source of ultrasound thanks to its remote operation, high resolution in the excitation area and broad frequency band. However, one of its drawbacks is the ...

  • Reevaluation of radiation reaction and consequences for light-matter interactions at the nanoscale 

    Escalora, M.; Vinceti, Maria Antonietta; Ceglia, Domenico de; Trull Silvestre, José Francisco; Cojocaru, Crina (2018-06-27)
    Article
    Open Access
    In the context of electromagnetism and nonlinear optical interactions, damping is generally introduced as a phenomenological, viscous term that dissipates energy, proportional to the temporal derivative of the polarization. ...

  • 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)
    Conference report
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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 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)
    Conference report
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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 ...

  • 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)
    Conference report
    Open Access
    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 ...

  • 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)
    Article
    Open Access
    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 ...

  • 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)
    Article
    Open Access
    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)
    Conference report
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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 ...

  • 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)
    Article
    Open Access
    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 ...

  • 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)
    Conference report
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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 ...

  • 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)
    Conference report
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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
    Open Access
    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 ...

  • Two-dimensional domain structures in Lithium Niobate via domain inversion with ultrafast light 

    Chen, Xin; Karpinski, Pawel; Shvedov, Vladlen; Wang, Bingxia; Trull Silvestre, José Francisco; Cojocaru, Crina; Boes, A.; Mitchell, A.; Krolikowski, Wieslaw; Sheng, Yan (2016)
    Article
    Open Access
    Periodic inversion of ferroelectric domains is realized in a lithium niobate crystal by focused femtosecond near-infrared laser beam. One and two-dimensional domain patterns are fabricated. Quasi-phase matched frequency ...

  • Type I and type II second harmonic generation of conically refracted beams 

    Turpin, Alex; Loiko, Yury; Kalkandjiev, Todor K.; Trull Silvestre, José Francisco; Cojocaru, Crina; Mompart, Jordi (2013-07-15)
    Article
    Open Access
    Type I and type II second harmonic generation (SHG) of a beam transformed by the conical refraction phenomenon are presented. We show that, for type I, the second harmonic intensity pattern is a light ring with a point of ...

  • Ultrashort pulse chirp determination via transverse auto-correlation in SBN crystal 

    Wang, Bingxia; Cojocaru, Crina; Inigo Sola, Inigo Sola; Wieslaw Krolikowski, Wieslaw Krolikowski; Yan Sheng, Yan Sheng; Vilaseca Alavedra, Ramon; Trull Silvestre, José Francisco (2015)
    Conference lecture
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    We determine the different initial chirp parameters of ultra-short pulses down to 30 fs via single-shot transverse auto-correlation method based on transverse second harmonic generation in SBN crystal with random distribution ...

  • Ultrashort pulse chirp measurement via transverse second-harmonic generation in strontium barium niobate crystal 

    Trull Silvestre, José Francisco; Sola, Ïñigo; Wang, Bingxia; Parra, Albert; Krolikowski, W.; Sheng, Y.; Vilaseca Alavedra, Ramon; Cojocaru, Crina (2015-06-01)
    Article
    Open Access
    Pulse compression in dispersive strontium barium niobate crystal with a random size and distribution of the anti-parallel orientated nonlinear domains is observed via transverse second harmonic generation. The dependence ...