Exploració per autor "Cojocaru, Crina"
Ara es mostren els items 1-20 de 65
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Beam focalization by chirped mirrors
(Optical Society of American (OSA), 2014)
Text en actes de congrés
Accés restringit per acord de confidencialitatA 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
(2014-10-15)
Article
Accés restringit per política de l'editorialWe 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 ... -
Broadband third harmonic generation in quadratic media with disordered ferroelectric domains
(2010)
Text en actes de congrés
Accés restringit per política de l'editorialWe 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
(2010)
Article
Accés restringit per política de l'editorialWe 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
(2018-01-22)
Article
Accés obertWe 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
(2018-05-09)
Article
Accés obertWe 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
(2015-01-12)
Article
Accés obertAn 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
(2020-02)
Article
Accés obertThis 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
(2013)
Comunicació de congrés
Accés restringit per política de l'editorialWe 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
(Multidisciplinary Digital Publishing Institute (MDPI), 2020-10-29)
Article
Accés obertIn 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
(Institute of Electrical and Electronics Engineers (IEEE), 2017)
Text en actes de congrés
Accés restringit per política de l'editorialWe 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
(2020-05-13)
Article
Accés obertWe 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
(2011-05-15)
Article
Accés obertIn 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
(Universitat Politècnica de Catalunya. Institut de Ciències de l'Educació, 2010-02-11)
Comunicació de congrés / Text en actes de congrés
Accés obertS’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
(International Society for Photo-Optical Instrumentation Engineers (SPIE), 2022)
Text en actes de congrés
Accés restringit per política de l'editorialWe 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
(Institute of Electrical and Electronics Engineers (IEEE), 2020)
Text en actes de congrés
Accés restringit per política de l'editorialWe 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
(2015-10-05)
Article
Accés obertWe 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
(2016-12-01)
Article
Accés obert -
Flat focusing mirror
(MACMILLAN PUBLISHERS LIMITED, 2014-09-17)
Article
Accés obertThe 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 focusing mirrors
(Institute of Electrical and Electronics Engineers (IEEE), 2015)
Text en actes de congrés
Accés restringit per política de l'editorialWe present the flat focusing mirror - the dielectric mirrors capable to focus and image the narrow beams in reflections. The mirrors are flat, and transversally invariant, i.e. have no optical axis. We consider two different ...
