Browsing by Author "Cojocaru, Crina"
Now showing items 1-20 of 66
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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 agreementA 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. -
Beam focalization in reflection from flat dielectric subwavelength gratings
Cheng, Yu Chieh; Zeng, H; Trullàs Simó, Joaquim; Cojocaru, Crina; Malinauskas, Mangirdas; Jukna, T; Wiersma, D.S.; Staliunas, Kestutis (2014-10-15)
Article
Restricted access - publisher's policyWe experimentally demonstrate the recently predicted effect of near-field focusing for light beams from flat dielectric subwavelength gratings (SWGs). This SWGs were designed for visible light 532 nm and fabricated by ... -
Below the surface: unraveling the intricacies of the nonlinear optical properties of aluminum through bound electrons
Scalora, Michael; Anson Hallman, Kent; Mukhopadhyay, Shroddha; Pruett, Samuel; Zappa, Dario; Comini, Elisabetta; Ceglia, Domenico de; Vincenti, Maria Antonietta; Akozbek, Neset; Trull Silvestre, José Francisco; Cojocaru, Crina (2024-08-20)
Article
Open AccessBy uncovering novel aspects of second harmonic generation in aluminum, we show that there are unusual and remarkable consequences of resonant absorption, namely an unexpectedly critical role that bound electrons play for ... -
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 policyWe 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 policyWe 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 AccessWe 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 AccessWe 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 AccessAn 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 ... -
Defect reconstruction by non-destructive testing with laser induced ultrasonic detection
Mohamed Selim, Hossameldin; Delgado Prieto, Miquel; Trull Silvestre, José Francisco; Pico Vila, Rubén; Romeral Martínez, José Luis; Cojocaru, Crina (2020-02)
Article
Open AccessThis work envisages a detailed study of two-dimensional defect localization and reconstruction, using laser generated ultrasound and its application as a remotely controlled non-destructive testing method. As an alternative ... -
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 policyWe 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 ... -
Directional ultrasound source for solid materials inspection: diffraction management in a metallic phononic crystal
Mohamed Selim, Hossameldin; Pico Vila, Rubén; Trull Silvestre, José Francisco; Delgado Prieto, Miquel; Cojocaru, Crina (Multidisciplinary Digital Publishing Institute (MDPI), 2020-10-29)
Article
Open AccessIn this work, we numerically investigate the diffraction management of longitudinal elastic waves propagating in a two-dimensional metallic phononic crystal. We demonstrate that this structure acts as an “ultrasonic lens”, ... -
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)
Conference report
Restricted access - publisher's policyWe 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 ... -
Electrodynamics of conductive oxides: intensity-dependent anisotropy, reconstruction of the effective dielectric constant, and harmonic generation
Scalora, Michael; Trull Silvestre, José Francisco; Ceglia, Domenico de; Vincenti, M. A.; Akozbek, Neset; Coppens, Zachary; Rodríguez Suñé, Laura; Cojocaru, Crina (2020-05-13)
Article
Open AccessWe study electromagnetic pulse propagation in an indium tin oxide nanolayer in the linear and nonlinear regimes. We use the constitutive relations to reconstruct the effective dielectric constant of the medium, and show ... -
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 AccessIn 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 AccessS’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 ... -
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)
Conference report
Restricted access - publisher's policyWe 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 ... -
Experimental and Theoretical Study of Second Harmonic Generation from an ITO Nanolayer
Rodríguez Suñé, Laura; Scalora, Michael; Johnson, Allan; Cojocaru, Crina; Akozbek, Neset; Coppens, Zachary; Pérez Salinas, Daniel; Wall, Simon; Trull Silvestre, José Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2020)
Conference report
Restricted access - publisher's policyWe present an experimental study of second harmonic generation from a 20nm-thick indium tin oxide layer in the proximity of its epsilon-near-zero condition. We report measurements of second harmonic efficiencies as a ... -
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 AccessWe 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 AccessThe 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 ...