Now showing items 1-20 of 38

  • 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)
    Conference report
    Restricted access - confidentiality agreement
    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)
    Conference report
    Restricted access - publisher's policy
    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
    Restricted access - publisher's policy
    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
    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. ...
  • Controllable coherent backscattering of light in disordered media filled with liquid crystal 

    Trull Silvestre, José Francisco; Cuevas, Marc; Salud Puig, Josep; Cojocaru, Crina; López Pérez, David Orencio (2018-05-09)
    Article
    Open Access
    We have investigated multiple scattering of light in a disordered system based on liquid crystals for a temperature-controllable random laser. Coherent backscattering measurements at several temperatures have been well ...
  • Controllable light diffraction in woodpile photonic crystals filled with liquid crystal 

    Ho, Chih-Hua; Cheng, Yu Chieh; Maigyte, Lina; Zeng, H; Trull Silvestre, José Francisco; Cojocaru, Crina; Wiersma, D.S.; Staliunas, Kestutis (2015-01-12)
    Article
    Open Access
    An approach to switching between different patterns of light beams transmitted through the woodpile photonic crystals filled with liquid crystals is proposed. The phase transition between the nematic and isotropic liquid ...
  • Coupling-mediated ghost resonance in mutually injected lasers 

    Martín Buldu, Javier; Martínez González, Cristina; Trull Silvestre, José Francisco; Torrent Serra, Maria del Carmen; García Ojalvo, Jordi (2005-03)
    Article
    Restricted access - publisher's policy
  • 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)
    Conference lecture
    Restricted access - publisher's policy
    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 ...
  • 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
    Open Access
    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 ...
  • Experiència de pràctiques personalitzades i xerrades professionals en el màster interuniversitari en fotònica 

    Royo Royo, Santiago; Vilaseca Ribalta, Ramon; Laguarta Bertran, Ferran; Pizarro Bondia, Carlos; Cojocaru, Crina; Trull Silvestre, José Francisco; Lázaro, José; Prat, Josep; Orriols i Tubella, Gaspar; Juvells, Ignasi (Universitat Politècnica de Catalunya. Institut de Ciències de l'Educació, 2010-02-11)
    Conference lecture / Conference report
    Open Access
    S’ha posat en funcionament una doble estratègia innovadora orientada a potenciar competències transversals en el Màster en Fotònica. Per una banda, s’ha engegat una assignatura de pràctiques personalitzades, que ...
  • Ferroelectric domain engineering by focused infrared femtosecond pulses 

    Chen, Xin; Karpinski, Pawel; Shvedov, Vladlen; Koynov, Kaloian; Wang, Bingxia; Trull Silvestre, José Francisco; Cojocaru, Crina; Krolikowski, Wieslaw; Sheng, Yan (2015-10-05)
    Article
    Open Access
    We demonstrate infrared femtosecond laser-induced inversion of ferroelectric domains. This process can be realised solely by using tightly focused laser pulses without application of any electric field prior to, in conjunction ...
  • Ferroelectric domain patterning with ultrafast light 

    Chen, Xin; Shvedov, Vladlen; Karpinski, Pawel; Koynov, Kaloian; Boes, A.; Mitchell, A.; Trull Silvestre, José Francisco; Cojocaru, Crina; Krolikowski, Wieslaw; Sheng, Yan (2016-12-01)
    Article
    Open Access
  • 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
    Open Access
    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 ...
  • Flat lensing in the visible frequency range by woodpile photonic crystals 

    Maigyte, Lina; Purlys, Vytautas; Trull Silvestre, José Francisco; Peckus, Martynas; Cojocaru, Crina; Gailevicius, Darius; Malinauskas, Mangirdas; Staliunas, Kestutis (2013-07-15)
    Article
    Open Access
    We experimentally demonstrate full two-dimensional focalization of light beams at visible frequencies by a three-dimensional woodpile photonic crystal. The focalization (the flat lensing) with focal distances of the order ...
  • Formation of collimated beams behind the woodpile photonic crystal 

    Trull Silvestre, José Francisco; Maigyte, Lina; Malinauskas, Mangirdas; Mizeikis, Vygantas; Juodkazis, Saulius; Cojocaru, Crina; Rutkauskas, Marius; Peckus, Martynas; Sirutkaitis, Valdas; Staliunas, Kestutis (2011-09-09)
    Article
    Open Access
    We experimentally observe formation of narrow laser beams behind the woodpile photonic crystal, when the beam remains well collimated in free propagation behind the crystal. We show that the collimation depends on the input ...
  • Fully Noncontact Hybrid NDT for 3D Defect Reconstruction Using SAFT Algorithm and 2D Apodization Window 

    Mohamed Selim, Hossameldin; Trull Silvestre, José Francisco; Delgado Prieto, Miquel; Pico Vila, Rubén; Romeral Martínez, José Luis; Cojocaru, Crina (Multidisciplinary Digital Publishing Institute (MDPI), 2019-05-08)
    Article
    Open Access
    Nondestructive testing of metallic objects that may contain embedded defects of different sizes is an important application in many industrial branches for quality control. Most of these techniques allow defect detection ...
  • Harmonic generation from metal-oxide and metal-metal boundaries 

    Escalora, M.; Vincenti, M. A.; de Ceglia, Domenico; Akozbek, Neset; Bloemer, M. J.; De Angelis, C.; Haus, J.W.; Vilaseca Alavedra, Ramon; Trull Silvestre, José Francisco; Cojocaru, Crina (American Physical Society (APS), 2018-08-20)
    Article
    Open Access
    We explore the outcomes of detailed microscopic models by calculating second- and third-harmonic generation from thin-film surfaces with discontinuous free-electron densities. These circumstances can occur in structures ...
  • Influence of liquid crystalline phases on the tunability of a random laser 

    Trull Silvestre, José Francisco; Salud Puig, Josep; Díez Berart, Sergio; López Pérez, David Orencio (American Chemical Society (ACS), 2017-05-30)
    Article
    Restricted access - publisher's policy
    In this paper, we report the temperature behavior of an optimized disordered photonic system-based liquid crystal by means of heat capacity and refractive index measurements. The scattering system is formed by a porous ...
  • Laser Ultrasound Inspection Based on Wavelet Transform and Data Clustering for Defect Estimation in Metallic Samples 

    Mohamed Selim, Hossameldin; Delgado Prieto, Miquel; Trull Silvestre, José Francisco; Romeral Martínez, José Luis; Cojocaru, Crina (Multidisciplinary Digital Publishing Institute (MDPI), 2019-01-30)
    Article
    Open Access
    Laser-generated ultrasound is a modern non-destructive testing technique. It has been investigated over recent years as an alternative to classical ultrasonic methods, mainly in industrial maintenance and quality control ...
  • Material defect reconstruction by non-destructive testing with laser induced ultrasonics 

    Mohamed Selim, Hossameldin; Delgado Prieto, Miquel; Trull Silvestre, José Francisco; Pico Vila, Rubén; Cojocaru, Crina (Institute of Physics (IOP), 2018)
    Conference report
    Open Access
    Aligned with current research efforts and industrial applications on nondestructive testing, in this work, a hybrid system combining remotely induced laser ultrasonics with conventional transducer detection is studied for ...