Search results for "Tantalate"
showing 7 items of 37 documents
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.
Effects of VTE Treatment on Composition of Lithium Tantalate Single Crystals
2011
The vapour transport equilibration (VTE) is used to change the Li/Ta ratio in lithium tantalate single crystals of different crystallographic orientations (Z-cut and Y/128°-cut). Treatment by VTE is shown to provide thin layers in lithium tantalate plates composition of which is close to stoichiometric while the values of the coercive field are different, much smaller compared with congruent single crystals. There are several mechanisms of diffusion of the Li+ ions in LiTaO3 under conditions of VTE the contribution of each being dependent on the crystallographic orientation of the sample.
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.
Surface periodic poling in congruent lithium tantalate
2006
The first demonstration of surface periodic poling of lithium tantalate at high voltages is reported. Periodic domain inversion with mark-to-space ratios close to the optimum 50:50 was successfully achieved down to micrometre periods with good uniformity and repeatability.
On lead-scandium tantalate solid solutions with high electrocaloric effect
1992
Abstract The PbSc0,5Ta0,5O3 solutions are found to be a useful material for active elements of microcryogenic devices based on electrocaloric effect. A temperature difference of ΔT = 1. 0-1.8 K at field intensities 20–30 kV/cm in the interval of 210–310 K can be achieved by simultaneous or separate introducing of Sb and Co ions in B-sites of the lattice. The most important contribution to the electrocaloric effect is due to field-induced Fn3m → R3m phase transition in the case of high ordering of B-ions in the perovskite structure ABO3.
Nonlinear Disorder Mapping Through Three-Wave Mixing
2010
We implement a simple and powerful approach to characterize the domain distribution in the bulk of quadratic ferroelectric crystals via far-field second-harmonic spectroscopy. The approach is demonstrated in a lithium tantalate sample with periodic electric field poling and random mark-to-space ratio.
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.