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Browsing by Author "Cojocaru, Crina"
Now showing items 21-40 of 67
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Flat focusing mirrors
Staliunas, Kestutis; Cheng, Yu-Chiech; Kicas, Simonas; Trull Silvestre, José Francisco; Cojocaru, Crina; Peckus, Martynas; Vilaseca Alavedra, Ramon; Drazdys, Ramutis (Institute of Electrical and Electronics Engineers (IEEE), 2015)
Conference report
Restricted access - publisher's policyWe 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 ... -
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 AccessWe 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 AccessWe 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 AccessNondestructive 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 at the nanoscale in strategic materials for nanophotonics
Rodríguez Suñé, Laura; Trull Silvestre, José Francisco; Scalora, Michael; Akozbek, Neset; Cojocaru, Crina (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2021)
Conference report
Restricted access - publisher's policyThe use of semiconductors, metals and conductive oxides in the process of fabrication of actual nano devices is at the front edge of nowadays technology, exploiting the properties of light propagation and localization at ... -
Harmonic generation from gold nanolayers: bound and hot electron contributions
Rodríguez Suñé, Laura; Trull Silvestre, José Francisco; Cojocaru, Crina; Akozbek, Neset; Ceglia, Domenico de; Vincenti, M. A.; Scalora, Michael (International Society for Photo-Optical Instrumentation Engineers (SPIE), 2021)
Conference report
Restricted access - publisher's policyCurrently, nanostructures are routinely fabricated and integrated in different photonic devices for a variety of purposes and applications. For instance, in order to engineer properly nano-antennas or filters, it is important ... -
Harmonic generation from gold nanolayers: bound and hot electron contributions to nonlinear dispersion
Rodríguez Suñé, Laura; Trull Silvestre, José Francisco; Cojocaru, Crina; Akozbek, Neset; Ceglia, Domenico de; Vincenti, M. A.; Scalora, Michael (2021-03-15)
Article
Open AccessUnderstanding how light interacts with matter at the nanoscale is pivotal if one is to properly engineer nano-antennas, filters and other devices whose geometrical features approach atomic size. We report experimental ... -
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 AccessWe 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 ... -
Harmonic generation from silicon membranes at visible and ultraviolet wavelengths
Anson Hallman, Kent; Rodríguez Suñé, Laura; Trull Silvestre, José Francisco; Cojocaru, Crina; Vincenti, Maria Antonietta; Akozbek, Neset; Vilaseca, Ramon; Scalora, Michael (2023-01-16)
Article
Open AccessNonlinear silicon photonics offers unique abilities to generate, manipulate and detect optical signals in nano-devices, with applications based on field localization and large third order nonlinearity. However, at the ... -
Harmonic generation in the opaque region of GaAs: the role of the surface and magnetic nonlinearities
Rodríguez Suñé, Laura; Trull Silvestre, José Francisco; Escalora, M.; Vilaseca Alavedra, Ramon; Cojocaru, Crina (2019-08-29)
Article
Open AccessPhase-locked second and third harmonic generation in the opaque region of a GaAs wafer is experimentally observed and analyzed both in transmission and reflection. These harmonic components, which are generated close to ... -
High-harmonic generation from subwavelength silicon films
Anson Hallman, Kent; Stengel, Sven; Wallace, Jaffray; Belli, Federico; Ferrera, Marcello; Vincenti, Maria Antonietta; Ceglia, Domenico de; Kivshar, Yu.; Akozbek, Neset; Mukhopadhyay, Shroddha; Trull Silvestre, José Francisco; Cojocaru, Crina; Scalora, Michael (2025-01-16)
Article
Open AccessRecent years have witnessed significant developments in the study of nonlinear properties of various materials at the nanoscale. Often, experimental results on harmonic generation are reported without the benefit of suitable ... -
Large nonlinear efficiency enhancement in the visible and UV range from plasmonic gold nanogratings
Cojocaru, Crina; Mukhopadhyay, Shroddha; Rodríguez Suñé, Laura; Vicenti, Maria Antonietta; Vilaseca Alavedra, Ramon; Scalora, Michael; Trull Silvestre, José Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2023)
Conference report
Restricted access - publisher's policyWe report a combined experimental/theoretical investigation on second and third harmonic generation from a plasmonic gold nanograting, that exhibits a plasmonic resonance in the near IR. The intense field localization leads ... -
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 AccessLaser-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 AccessAligned 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 ... -
Nonlinear duffing oscillator model for third harmonic generation
Scalora, Michael; Vincenti, M. A.; Ceglia, Domenico de; Cojocaru, Crina; Grande, Manuel; Haus, J.W. (2015-10-01)
Article
Open AccessWe employ a classical, nonlinear Lorentz-Duffing oscillator model to predict third harmonic conversion efficiencies in the ultrafast regime, from a variety of metal nanostructures, including smooth, isolated metal layers, ... -
Nonspreading Light Pulses in Photonic Crystals
Staliunas, Kestutis; Serrat Jurado, Carles; Herrero Simon, Ramon; Cojocaru, Crina; Trull Silvestre, José Francisco (2005-05)
Research report
Open AccessWe investigate propagation of light pulses in photonic crystals in the vicinity of the zero-diffraction point. We show that Gaussian pulses due to nonzero width of their spectrum spread weakly in space and time during the ... -
Observation of azimuthal modulation instability and formation of patterns of optical solitons in a quadratic nonlinear crystal
Petrov, Dimitri; Torner Sabata, Lluís; Martorell Pena, Jordi; Vilaseca Alavedra, Ramon; Pérez Torres, Juan; Cojocaru, Crina (1998-09)
Article
Restricted access - publisher's policyWe 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
Cojocaru, Crina; Rodríguez Suñé, Laura; Escalora, M.; Trull Silvestre, José Francisco (Institute of Electrical and Electronics Engineers (IEEE), 2019)
Conference report
Open AccessWe 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
Roppo, Vito; D'Aguanno, G.; Cojocaru, Crina; Raineri, F.; Trull Silvestre, José Francisco; Vilaseca Alavedra, Ramon; Raj, R; Scalora, M. (2009)
Conference report
Restricted access - publisher's policyDuring 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
Mohamed Selim, Hossameldin; Pico Vila, Rubén; Trull Silvestre, José Francisco; Delgado Prieto, Miquel; Cojocaru, Crina (Sociedad Española de Acústica (SEA), 2018)
Conference report
Restricted access - publisher's policyLaser 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 ...