Search results for "Lithium"
showing 10 items of 680 documents
Nanostructured Material Fabrication for Energy Conversion
2011
The electrochemical deposition is a suitable via to fabricate nanostructured materials for energy conversion, and for other purposes. This paper deals with the electrochemical synthesis of nanostructured alloys and ruthenium oxide, which can be used in Li-ion batteries and polymer electrolyte membrane electrolyzers.
Dual-polarization-pump CW laser operation in Nd3+:LiNbO3 channel waveguides fabricated by reverse proton exchange
2008
Abstract In this work, continuous-wave laser action at 1084.5 nm at room temperature in LiNbO 3 :Nd 3+ channel waveguides, fabricated by reverse proton exchange (RPE), is reported. The sample was pumped at λ = 808 nm in either σ or π-polarized configurations, TE- and TM-pumping schemes, being the laser emission π-polarized at all power levels. The laser characteristics, as function of the pumping scheme (TE or TM), have been obtained. In both cases, the laser emission was stable, without any reduction in the output power even under continuous pump operation at maximum power at room temperature, indicating high resistance to photorefractive damage.
Investigation of hydrogen and deuterium impact on the release of tritium from two-phase lithium ceramics under reactor irradiation
2022
In the development of fusion energy, an important task is the study and improvement of tritium production technologies. In this case, one of the most promising materials for tritium generation is lithium ceramics. Considering the importance of the task, numerous studies are aimed at solving the problem of determining the parameters and mechanisms of tritium release in lithium-containing materials. This paper presents the results of a study of tritium release processes from two-phase lithium ceramics of Li$_{4}$SiO$_{4}$/Li$_{2}$TiO$_{3}$ during reactor irradiation when hydrogen and deuterium are injected into the chamber with irradiated samples. The mechanisms regularities of the tritium yi…
Nanopatterned ferroelectric crystals for parametric generation
2006
We report on recent results by surface periodic poling on lithium niobate and lithium tantalate. Such approach allows periodic inversion of the second order susceptibility with nanoscale features using insulating masks. We achieved a world-best 200 nm feature size, as well as good compatibility with alpha-phase proton exchanged channel waveguides in lithium niobate. Preliminary results of surface periodic poling in lithium tantalate also show similar characteristics. Surface poling is best suited for integrated optics devices in technologically-demanding configurations such as backward second harmonic generation and counter propagating optical parametric amplification
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.
Guided-wave frequency doubling in surface periodically poled lithium niobate: competing effects
2007
We carried out second-harmonic generation in quasi-phase-matched ? -phase lithium niobate channel waveguides realized by proton exchange and surface periodic poling. Owing to a limited ferroelectric domain depth, we could observe the interplay between second-harmonic generation and self-phase modulation due to cascading and cubic effects, resulting in a nonlinear resonance shift. Data reduction allowed us to evaluate both the quadratic nonlinearity in the near infrared as well as the depth of the uninverted domains. © 2007 Optical
Continuous-Wave Backward Frequency Doubling in Periodically Poled Lithium Niobate
2010
We report on backward second-harmonic- generation in periodically poled lithium niobate with a 3.2 micron QPM period. A tunable continuous-wave Ti:Sapphire laser allowed us exciting two resonant orders. Experimental data compared well with standard theory.
Optical properties of Cr3+ and Ni2+ ions in MgO, LiNbO3 and LMA
1995
Abstract The electronic structures of Co2+ and Ni2+ ions are obtained by the molecular orbital LCGTO-LSD method. Electrostatic matrix calculations are performed for d3 and d8 configurations. Theoretical optical data are discussed in function of the impurity site location in the crystal cell.
Quadrupole interaction of $^{8}$Li and $^{9}$Li in LiNbO$_{3}$ and the quadrupole moment of $^{9}$Li
1988
The quadrupole interaction of nuclear spin polarized8Li (I=2) and9Li (I=3/2) in LiNbO3 has been studied at room temperature. The polarization was achieved by optical pumping of a fast atomic beam with circularly polarized laser light. The atoms were implanted into a hexagonal LiNbO3 single crystal and the quadrupole splitting ofβ-NMR spectra was measured. A ratio of ¦Q(9Li)/Q(8Li)¦=0.88(4) for the nuclear quadrupole moments was deduced, yielding a new value of ¦Q(9Li)¦=25.3 (9) mb for the quadrupole moment of9Li.
LASER SPECTROSCOPY WITH A COOLER RING AT THE ESR (GSI) AND THE TSR (MPI HEIDELBERG)
1992
At the TSR cooler ring at Heidelberg, laser studies were carried out using singly charged lithium and beryllium ions. Laser spectroscopy of relativistic lithium ions (v=0.04c) yielded signals with a narrow linewidth, suitable for an experimental test of special relativity. A dramatic reduction of the beam temperature, as defined by the longitudinal velocity spread, was achieved via laser cooling in both cases. At the ion energies available at ESR it will become possible to prepare and store bare ions up to U92+. Electron cooling was succesfully demonstrated for hydrogen-like Bi82+ ions, where a laser experiment is scheduled to study the ground-state hyperfine splitting.