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    • El 50 aniversari del Làser: fites aconseguides en ciència i tecnologia, i perspectives de futur 

      Vilaseca Alavedra, Ramon (2010-05-07)
      Audiovisual
      Accés obert
      Un làser és un dispositiu que utilitza l'emissió estimulada o induïda per generar un feix de llum. Però què ha fet fins ara i quin és el seu futur?

    • Activitats del grup de recerca Dinàmica No lineal, Òptica no lineal i Làsers 

      Vilaseca Alavedra, Ramon (Campus de Terrassa de la UPC, 2013-06-13)
      Text en actes de congrés
      Accés obert

    • Activitats del Grup de Recerca en Dinàmica no lineal, Òptica no lineal i Làsers (DONLL)" 

      Vilaseca Alavedra, Ramon (Campus de Terrassa de la UPC, 2013-06-13)
      Text en actes de congrés
      Accés obert

    • Adiabatic population transfer in the D1 transition of 39K 

      Fernández Soler, Juan José; Font García, Josep Lluís; Vilaseca Alavedra, Ramon (2018-06-22)
      Article
      Accés obert
      Four-photon stimulated Raman adiabatic passage–like (STIRAP-like) processes in the frame of the D1 optical transition line of atomic 39K are investigated theoretically by means of a rigorous model that takes into account ...

    • All optical implementation of a stochastic logic gate using a VCSEL with external optical injection 

      Perrone, S.; Masoller Alonso, Cristina; Vilaseca Alavedra, Ramon (2011)
      Text en actes de congrés
      Accés obert
      We perform numerical simulations of the dynamics of two VCSELs optically coupled in a master-slave configuration. We show that the interplay of nonlinearity and spontaneous emission noise can yield logic behavior, and the ...

    • Beam focalization by chirped mirrors 

      Cheng, Yu Chieh; Peckus, Martynas; Kicas, Simonas; Trull Silvestre, José Francisco; Cojocaru, Crina; Vilaseca Alavedra, Ramon; Drazdys, Ramutis; Staliunas, Kestutis (Optical Society of American (OSA), 2014)
      Text en actes de congrés
      Accés restringit per acord de confidencialitat
      A novel application of chirped dielectric mirrors for narrow beam focalization is proposed and demonstrated numerically and experimentally. Analogy to temporal dispersion compensation by chirped dielectric mirrors is discussed.

    • Broadband third harmonic generation in quadratic media with disordered ferroelectric domains 

      Kalinowski, K.; Roppo, Vito; Wang, W.; Neshev, Dragomir N.; Kong, Y.; Cojocaru, Crina; Trull Silvestre, José Francisco; Vilaseca Alavedra, Ramon; Staliunas, Kestutis; Krolikowski, Wieslaw; Kivshar, Yu. (2010)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      We study nonlinear frequency generation in media with random ferroelectric domain structure. We show that randomness enables one to realize broadband third harmonic generation via cascading of two second order quasi-phase ...

    • Cavity behavior of second and third harmonic inhomogeneous solutions of Maxwell’s equations 

      Roppo, Vito; Cojocaru, Crina; Trull Silvestre, José Francisco; Vilaseca Alavedra, Ramon; Scalora, M. (2010)
      Article
      Accés restringit per política de l'editorial
      We study second and third harmonic generation of ultrashort pulses in a cavity environment and focus on the role of a phase locking phenomenon that causes the pump to trap and drag the generated harmonic fields. The results ...

    • 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
      Accés obert
      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. ...

    • Controlling the likelihood of rogue waves in an optically injected semiconductor laser via direct current modulation 

      Perrone, Sandro; Vilaseca Alavedra, Ramon; Zamora-Munt, Jordi; Masoller Alonso, Cristina (2014-03-06)
      Article
      Accés obert
      Extreme and rare events are nowadays the object of intensive research. Rogue waves are extreme waves that appear suddenly in many natural systems, even in apparently calm situations. Here we study numerically the rogue ...

    • Diffraction control of reflected beam by chirped mirror 

      Cheng, Yu Chieh; Peckus, Martynas; Kicas, S.; Trull Silvestre, José Francisco; Cojocaru, Crina; Vilaseca Alavedra, Ramon; Drazdys, R.; Staliunas, Kestutis (2013)
      Comunicació de congrés
      Accés restringit per política de l'editorial
      We propose and demonstrate a novel functionality of chirped mirror for monochromatic light beams: a diffraction control in reflections resulting in focusing or imaging of beams. The chirped mirrors, commonly used for ...

    • Domain statistics analysis of random nonlinear crystals via second harmonic generation 

      Wang, Bingxia; Cojocaru, Crina; Krolikowski, Wieslaw; Switowski, K; Yan Sheng, Yan Sheng; Akhouayri, H.; Vilaseca Alavedra, Ramon; Scalora, Michael; Trull Silvestre, José Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2017)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      We demonstrate an indirect non-destructive optical method for the characterization of ferroelectric domain size and distribution based on the analysis of the generated second harmonic spatial distribution. This method is ...

    • Einstein : física, enginyeria i matemàtiques 

      Vilaseca Alavedra, Ramon (2004-09-15)
      Audiovisual
      Accés obert
      "L’any 2005 fou declarat Any Mundial de la Física. Coincideix amb el centenari de publicacions d’Albert Einstein sobre el moviment brownià, sobre els quanta de llum i sobre relativitat especial. Les idees d’Einstein ...

    • Einstein: física, tecnologia i matemàtiques 

      Vilaseca Alavedra, Ramon (2014-01-31)
      Altres
      Accés obert
      "L’any 2005 fou declarat Any Mundial de la Física. Coincideix amb el centenari de publicacions d’Albert Einstein sobre el moviment brownià, sobre els quanta de llum i sobre relativitat especial. Les idees d’Einstein ...

    • El láser, fuente de fenómenos y dinámicas no lineales 

      Vilaseca Alavedra, Ramon (2010-10-01)
      Article
      Accés restringit per política de l'editorial

    • ELECTRICITAT I MAGNETISME (Examen 2n Quadr.) 

      Vilaseca Alavedra, Ramon (Universitat Politècnica de Catalunya, 2005-06-06)
      Examen
      Accés restringit a la comunitat UPC

    • Enhanced efficiency of the second harmonic inhomogeneous component in an opaque cavity 

      Roppo, Vito; Raineri, F.; Raj, R; Sagnes, I.; Trull Silvestre, José Francisco; Vilaseca Alavedra, Ramon; Scalora, M.; Cojocaru, Crina (2011-05-15)
      Article
      Accés obert
      In this Letter, we experimentally demonstrate the enhancement of the inhomogeneous second harmonic conversion in the opaque region of a GaAs cavity with efficiencies of the order of 0.1% at 612nm, using 3 ps pump pulses ...

    • Entrevista del professor Ramon Vilaseca al professor Daniel Gauthier. 

      Gauthier, Daniel; Vilaseca Alavedra, Ramon (2012-04-17)
      Audiovisual
      Accés obert
      Talking & Researching

    • Experimental and theoretical study of second and third harmonic generation in amorphous silicon 

      Rodríguez Suñé, Laura; Scalora, Michael; Cojocaru, Crina; Akozbek, Neset; Vilaseca Alavedra, Ramon; Trull Silvestre, José Francisco (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2022)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      We report contrasted experimental and theoretical results on second and third harmonic generation from an amorphous silicon nanolayer. We perform this study by analysing the harmonic optical signals generated when fs and ...

    • Flat focusing mirror 

      Cheng, Yu Chieh; Kicas, Simonas; Trull Silvestre, José Francisco; Peckus, Martynas; Cojocaru, Crina; Vilaseca Alavedra, Ramon; Drazdys, Ramutis; Staliunas, Kestutis (MACMILLAN PUBLISHERS LIMITED, 2014-09-17)
      Article
      Accés obert
      The control of spatial propagation properties of narrow light beams such as divergence, focusing or imaging are main objectives in optics and photonics. In this letter, we propose and demonstrate experimentally a flat ...