Exploració per autor "Cojocaru, Crina"
Ara es mostren els items 35-54 de 65
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Observation of azimuthal modulation instability and formation of patterns of optical solitons in a quadratic nonlinear crystal
(1998-09)
Article
Accés restringit per política de l'editorialWe 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 harmonic generation in the opaque region of GaAs
(Institute of Electrical and Electronics Engineers (IEEE), 2019)
Text en actes de congrés
Accés obertWe demonstrate second and third harmonic generation from a GaAs substrate, well-below the absorption edge, in both transmission and reflection geometries. The pump is tuned at 1064 nm, in the transparency range, while the ... -
Phase locked second harmonic etalon localization
(2009)
Text en actes de congrés
Accés restringit per política de l'editorialDuring 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
(Sociedad Española de Acústica (SEA), 2018)
Text en actes de congrés
Accés restringit per política de l'editorialLaser 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 ... -
Photonic crystal spatial filtering in broad aperture diode laser
(2019-10-02)
Article
Accés obertBroad aperture semiconductor lasers usually suffer from low spatial quality of the emitted beams. Due to the highly compact character of such lasers, the use of conventional intracavity spatial filters is problematic. We ... -
Reevaluation of radiation reaction and consequences for light-matter interactions at the nanoscale
(2018-06-27)
Article
Accés obertIn 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. ... -
Resonant, broadband, and highly efficient optical frequency conversion in semiconductor nanowire gratings at visible and UV wavelengths
(2019-08-01)
Article
Accés restringit per política de l'editorialUsing a hydrodynamic approach, we examine bulk- and surface-induced second- and third-harmonic generationfrom semiconductor nanowire gratings having a resonant nonlinearity in the absorption region. We demonstrateresonant, ... -
Retrieving linear and nonlinear optical dispersions of matter: combined experiment-numerical ellipsometry in silicon, gold and indium tin oxide
(2021-09-17)
Article
Accés obertWe have presented a combined experimental and numerical method that can be used to predict complex nonlinear dispersion curves in almost any material, based exclusively on the experimental determination of harmonic generation ... -
Second and third harmonic generation from gold nanolayers: experiment versus theory
(EPJ Web of Conferences, 2021)
Text en actes de congrés
Accés obertThe use of semiconductors, metals, or ordinary dielectrics in the process of fabrication of nanodevices is at the front edge of nowadays technology, exploiting the properties of light propagation and localization at ... -
Second and third harmonic generation in disordered quadratic nonlinear media: application to short-pulse characterization
(2010)
Text en actes de congrés
Accés restringit per política de l'editorialWe 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 from an ITO nanolayer: experiment versus theory
(International Society for Photo-Optical Instrumentation Engineers (SPIE), 2020)
Text en actes de congrés
Accés obertWe report a comparative experimental and theoretical study of second harmonic generation from a 20nm-thick indium tin oxide nanolayer in the proximity of the epsilon-near-zero condition. We record the efficiency of the ... -
Second-harmonic generation in disordered quadratic media: role of a ferroelectric domain structure
(2010)
Text en actes de congrés
Accés obertWe 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 ... -
Second-harmonic generation in disordered quadratic media: role of a ferroelectric domain structure
(2010)
Text en actes de congrés
Accés restringit per política de l'editorialNaturally 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 ... -
Signatures of light-beam spatial filtering in a three-dimensional photonic crystal
(2010-08-13)
Article
Accés obertWe 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 ... -
Single-shot d-scan technique for ultrashort laser pulse characterization using transverse second-harmonic generation in random nonlinear crystals
(2020-07-15)
Article
Accés obertWe demonstrate a novel dispersion-scan (d-scan) scheme for single-shot temporal characterization of ultrashort laser pulses. The novelty of this method relies on the use of a highly dispersive crystal featuring antiparallel ... -
Spatial filtering in broad area semiconductor laser using photonic crystal
(2020)
Comunicació de congrés
Accés restringit per política de l'editorialIn high power regimes, broad area semiconductor lasers usually suffer from poor beam quality due to their asymmetric beam divergence, large beam quality factor (M2) and from the absence of any intrinsic filtering mechanism ... -
Spatial filtering in edge-emitting lasers by intracavity chirped photonic crystals
(2020-10-01)
Article
Accés obertIn this work, we report an experimental and numerical study of the intracavity spatial filtering in edge-emitting lasers using a chirped photonic crystal (PhC) as the filtering element in the near-field domain. We provide ... -
Study of second and third harmonic generation from an indium tin oxide nanolayer: Influence of nonlocal effects and hot electrons
(2020-01-03)
Article
Accés obertWe report comparative experimental and theoretical studies of the second and third harmonic generation from a 20 nm-thick indium tin oxide layer in proximity of the epsilon-near-zero condition. Using a tunable optical ... -
Surface and bulk harmonic generation in the opaque region of GaAs
(International Society for Photo-Optical Instrumentation Engineers (SPIE), 2019)
Comunicació de congrés
Accés restringit per política de l'editorialWe demonstrate second and third harmonic generation from a GaAs substrate, well-bellow the absorption edge, in both transmission and reflection geometries. The pump is tuned at 1064 nm, in the transparency range, while the ... -
Tailoring Cerenkov second-harmonic generation in bulk nonlinear photonic crystal
(2011-07-01)
Article
Accés obertWe 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 ...
