0000000000098091
AUTHOR
Stefano Riva Sanseverino
showing 59 related works from this author
Completely dielectric E-field sensor based on a Lithium Niobate MZI
2008
We report an IO electric field sensor based on a particular cofiguration of Mach-Zehnder interferometer. The device, fabricated on a Lithium Niobate substrate, is totally dielectric, without any presence of metallic electrodes. The Mach-Zehnder was achieved through soft proton exchange and poling technologies. A modulation depth of 92% and an half wave voltage of 107.8 V were measured using a triangular voltage signal.
Sorgente laser multilinea NIR-RGB in guide ottiche RPE su Nd:LiNbO3
2004
Ion Plating Plasma Assisted Deposition from Thermal Sources for Decorative Coatings
2008
Growth and characterization of horizontally suspended CNTs across TiN electrode gaps.
2010
A technique is proposed to grow horizontal carbon nanotubes (CNTs) bridging metal electrodes and to assess their electrical properties. A test structure was utilized that allows for selective electrochemical sidewall catalyst placement. The selectivity of the technique is based on the connection of the desired metal electrodes to the silicon substrate where the potential for electrochemical deposition was applied. Control over the Ni catalyst size (15-30 nm) and density (up to 3 x 10(11) particles cm(-2)) is demonstrated. Horizontal CNTs with controlled diameter and density were obtained by CVD growth perpendicular to the sidewalls of patterned TiN electrode structures. Electrode gaps with …
Time resolved confocal luminescence investigations on reverse proton exchange Nd : LiNbO3 channel waveguides
2009
In this work we report on the time and spatial resolved fluorescence of Neodymium ions in LiNbO(3) channel waveguides fabricated by Reverse Proton Exchange. The analysis of the fluorescence decay curves obtained with a sub-micrometric resolution has evidenced the presence of a relevant fluorescence quenching inside the channel waveguide. From the comparison between diffusion simulations and the spatial dependence of the (4)F(3/2) fluorescence decay rate we have concluded that the observed fluorescence quenching can be unequivocally related to the presence of H+ ions in the LiNbO(3) lattice. Nevertheless, it turns out that Reverse Proton Exchange guarantees a fluorescence quenching level sig…
Analysis of Lithium Niobate Surface Layer after Electric Field Periodic Poling and Proton Exchange
2004
Random quasi-phase-matched second harmonic generation in periodically poled lithium tantalate
2009
We experimentally observed and explained bulk second harmonic generation via random quasi-phase-matching, derived from a periodically poled lithium tantalate sample with a randomly patterned mark-to-space-ratio.
Studio della Nonlinearità Quadratica di Zincoblende per la Generazione di TeraHertz in Guida d'Onda: un Confronto di Cristalli Differenti
2009
DFG TeraHertz generation can approach the quantum efficiency limit with much lower peak powers than bulk experiments. We give details on the model and on the waveguide geometry.
Continuous-Wave Backward Frequency Doubling in Periodically Poled Lithium Niobate
2010
Surface Plasmon Resonance Optical Biosensors for Mannoproteins Detection
2007
Surface periodic poling in congruent lithium tantalate
2006
Modelling of Laser Operation in RPE Nd3+:LiNbO3 Channel Waveguides
2006
In this work, laser action in RPE Nd3+:LiNbO3 is modelled by using the overlapping integrals method. Different pumping schemes, TE or TM, have been considered in order to reproduce the experimental measurements. Calculated results indicate that the slope efficiency remains basically independent on the pumping scheme while the threshold pump power increases for TE pumping.
Studio della nonlinearità quadratica di zincoblende per la generazione di TeraHertz in guida d'onda: un confronto di cristalli differenti
2009
DFG TeraHertz generation can approach the quantum efficiency limit with much lower peak powers than bulk experiments. We give details on the model and on the waveguide geometry.
GENERAZIONE DI SECONDA ARMONICA MEDIANTE RANDOM QUASI-PHASE-MATCHING IN TANTALATO DI LITIO POLATO PERIODICAMENTE
2009
We experimentally observed and explained bulk Second Harmonic Generation via Random Quasi-Phase-Matching, derived from a periodically poled Lithium Tantalate sample with a randomly patterned mark-to-space-ratio.
Stable proton exchanged waveguides in Lithium Tantalate
2008
alpha, beta(1), and kappa(2) phases are investigated for planar waveguide fabrication by proton exchange in congruent lithium tantalate. The effective indices of planar waveguide eigenmodes were monitored over time, revealing that the exchange process induces aging instabilities in all phases except alpha.
Duplicazione di frequenza in guide d'onda in Niobato di Litio con poling periodico: ruolo dell'assorbimento multifotoni
2008
Sensore di campo elettrico completamente dielettrico in ottica integrata.
2008
We report an electric field sensor based on a particular cofiguration of Mach-Zehnder interferometer (MZI). The device, fabricated on a Lithium Niobate substrate, is totally dielectric, without any presence of metallic electrodes. A modulation depth of 92% and an half wave voltage of 107.8 V were measured using a triangular voltage signal.
MATCHING THIN LAYER FOR SURFACE PLASMON RESONANCE TUNING ON LITHIUM NIOBATE WAVEGUIDES
2006
Polarization effects on the laser operation in RPE Nd3+:LiNbO3 channel waveguides
2005
University of Palermo: Exploiting the Optical Quadratic Nonlinearity of Zinc-Blende Semiconductors for Guided-Wave Terahertz Generation: A Material C…
2012
Content synopsis of the following paper: Matteo Cherchi, Alberto Taormina, Alessandro C. Busacca, Roberto L. Oliveri, Saverio Bivona, Alfonso C. Cino, Salvatore Stivala, Stefano Riva Sanseverino, and Claudio Leone, "Exploiting the Optical Quadratic Nonlinearity of Zinc-Blende Semiconductors for Guided-Wave Terahertz Generation: A Material Comparison", IEEE Journal of Quantum Electronics, Vol. 46, N. 3, March 2010
Surface Plasmon Resonance Measurement of Neutravidin Layer on Gold Thin Film
2006
Nano-domains definition in congruent lithium niobate by surface periodic electric-field poling
2005
Generazione di seconda armonica nel vicino infrarosso per quasi-accordo di fase in guide a scambio protonico in niobato di litio con polarizzazione p…
2006
Generazione di Seconda Armonica per Quasi-Phase-Matching Random in Tantalato di Litio con Poling Periodico
2009
We experimentally observed and explained bulk Second Harmonic Generation via Random Quasi-Phase-Matching, derived from a periodically poled Lithium Tantalate sample with a randomly patterned mark-to-space-ratio.
Second harmonic generation in coupled LiNbO3 waveguides by reverse-proton exchange
2003
We demonstrate second harmonic generation of a near-infrared pump in a nonlinearly coupled system formed by longitudinally uniform proton- and reverse-proton-exchanged LiNbO/sub 3/ planar waveguides. Phase- and mode-matched transverse electric (TE/sub 0/) frequency doubling into transverse magnetic higher order guided modes is achieved through temperature control, in agreement with the model.
UV quasi-phase-matched second harmonic in LiTaO3 channel waveguide
2008
Guide a scambio protonico in Tantalato di Litio stabili nel tempo
2008
Le Tecnologie dell'Informazione e della Comunicazione a servizio del Turismo Relazionale
2004
Analysis of Lithium Niobate Surface after Electric Field Periodic Poling and Proton Exchange
2004
Confocal optical techniques to study channel waveguides in LiNbO3
2008
Surface Periodic Poling in Lithium Niobate and Lithium Tantalate
2005
Periodic Poling of Lithium Niobate crystals (PPLN) by means of electric field has revealed the best technique for finely tailoring PPLN structures and parameters, which play a central role in many current researches in the field of nonlinear integrated optics. Besides the most studied technique of bulk poling, recently a novel technique where domain inversion occurs just in a surface layer using photoresist or silica masks has been devised and studied. This surface periodic poling (SPP) approach is best suited when light is confined in a thin surface guiding layer or stripe, as in the case of optical waveguide devices. Also, we found that SPP respect to bulk poling offers two orders of magn…
Generazione di seconda armonica per quasi accordo di fase in guide a canale su LiNbO3 periodicamente polato in superficie.
2005
Characterization of PP-cLT Waveguides for phase conjugation in the C + L band of Optical Communications
2010
Correlated Channel Model for terrestrial Free Space Optics and project specifications evaluation of LT code in OOK modulation
2011
Free Space Optics is a wireless line-of-sight communication system able to offer good bandwidth performance as well as straightforward installation and relocation. So that it represents a modern technology that allow to realize large bandwidth communication particularly when it is not possible to employ physical cable or radio technologies. Examples of FSO applications are: wireless backaul, fiber backup, temporary links, metro network extension and last mile access[1]. FSO is based on optical signals propagation in air and that is why it suffers of impairments which depend on atmospheric conditions. In detail, FSO suffers of scattering (i. e. Rayleigh and Mie) losses, absorption and scinti…
Ultraviolet quasi-phase-matched second harmonic generation in surface periodically poled Lithium Niobate optical waveguides
2006
Modelling of Quasi-TM0,0 Laser Operation in RPE:Nd3+:LiNbO3 Channel Waveguides.
2007
Growth and Electrical Characterization of Horizontally Aligned CNTs
2009
Nickel catalyst nanoparticles acting as nucleating seeds for carbon nanotube (CNT) growth were selectively deposited on the sidewalls of titanium nitride (TiN) electrodes by electrochemical deposition (ECD) from a Ni2+ electrolyte solution. Horizontal aligned CNTs were grown selectively from the sidewalls of these TiN electrodes forming a bridging CNT contact between the electrode gaps. Current-voltage measurements demonstrated this could be a promising technique towards nanoscale interconnections and nanoelectronic devices with resistance values for the bridging CNTs as low as 300Ω.
High resolution x-ray investigation of periodically poled lithium tantalate crystals with short periodicity
2009
Domain engineering technology in lithium tantalate is a well studied approach for nonlinear optical applications. However, for several cases of interest, the realization of short period structures (< 2 ��m) is required, which make their characterization difficult with standard techniques. In this work, we show that high resolution x-ray diffraction is a convenient approach for the characterization of such structures, allowing us to obtain in a nondestructive fashion information such as the average domain period, the domain wall inclination, and the overall structure quality.
AUTOFOCALIZZAZIONE VIA RANDOM QUASI-PHASE-MATCHING IN GUIDE D’ONDA DI TANTALATO di LITIO
2010
We observe self-localization of light beams via second harmonic generation in a quasi-phase-matched proton-exchanged Lithium Tantalate slab waveguide in the presence of a random component of the periodically-poled grating.
Nanotecnologie in Niobato di Litio per la conversione di frequenza in ottica integrata nel campo UV.
2007
Quasi Phase Matched UV Second Harmonic Generation in Lithium Tantalate soft PE Waveguides
2008
We report on first experimental results on UltraViolet second-harmonic generation by first-order quasiphase-matching in a surface periodically poled proton exchanged Lithium Tantalate waveguide. We have achieved a good compatibility with alpha phase proton exchanged channel waveguides in Lithium Tantalate. We held the sample in a temperature controlled oven kept at a constant temperature of 250 °C, to reduce photorefractive damage. The pump source was a Ti-Sapphire laser with a tunability range of 700 - 980 nm and a 40-GHz linewidth. Continuous wave UV light at 365.4 nm was produced with a conversion efficiency of 6.6% W-1cm-2.
Fabbricazione di guide PE in LiTaO3 prive di instabilità
2008
Role of nonlinear absorption during frequency doubling in lithium niobate waveguides.
2007
GENERAZIONE DI SECONDA ARMONICA RETRO-PROPAGANTE IN NIOBATO DI LITIO CON POLING PERIODICO
2010
We report on backward second-harmonic-generation in bulk periodically poled congruent lithium niobate with a 3.2 micron period. A tunable continuous-wave Ti:Sapphire laser allowed us exciting two resonant quasi-phase-matched orders. Resonances were also resolved by temperature tuning.
Progettazione e realizzazione di biosensori a risonanza plasmonica superficiale in ottica integrata.
2007
Generazione di luce UV per interazione QPM/SHG in guida ottica di niobato di litio congruente
2006
Ingegnerizzazione dei domini ferroelettrici nel niobato di litio per applicazioni nonlineari
2005
Nanotecnologie SPPLN con maschere in silica e fotoresist
2004
Exploiting the optical quadratic nonlinearity of zinc-blende semiconductors for guided-wave terahertz generation: A material comparison
2010
We present a detailed analysis and comparison of dielectric waveguides made of CdTe, GaP, GaAs and InP for modal phase matched optical difference frequency generation (DFG) in the terahertz domain. From the form of the DFG equations, we derived the definition of a very general figure of merit (FOM). In turn, this FOM enabled us to compare different configurations, by taking into account linear and nonlinear susceptibility dispersion, terahertz absorption, and a rigorous evaluation of the waveguide modes properties. The most efficient waveguides found with this procedure are predicted to approach the quantum efficiency limit with input optical power in the order of kWs.
Second Harmonic Generation via Random Quasi-phase Matching in a Periodically Poled Lithium Tantalate Waveguide
2011
We observe second harmonic generation via random quasi phase matching in a 1.5μm periodically poled lithium tantalate. The presence of a slab waveguide allows the comparison between bulk and guided wave configurations.
Prima dimostrazione di generazione UV per QPM in guide ottiche PE il LiTaO3
2008
Frequency doubling in surface periodically-poled lithium niobate waveguides: role of cascading and nonlinear absorption
2008
Nanotecnologie SPPLN per Dispositivi a Cristalli Fotonici
2004
Interference-Based Chromatic Coatings by Ion Plating Plasma Assisted Deposition Technology
2010
The goal of replacing widespread and inexpensive galvanic treatments with suitable vacuum deposition techniques, in order to eliminate the environmental hazards and their polluting effects, is becoming, in some cases, more tangible. Shorter cleaning cycles, shorter pump-down times, reduced heating times of substrates and higher deposition rates allow the costs of new plasma-assisted processes to become competitive with respect to galvanic ones. Moreover, vacuum treatments offer superior mechanical and optical properties and non-conductive substrates (like glass, ceramics, plastics) can be more easily coated. This work describes the results obtained with Ion Plating Plasma Assisted depositio…