An experimental demonstration of quantum-correlations is presented. Energy and time entangled photons at wavelengths of 704 and 1310 nm are produced by parametric downconversion in KNbO3 and are sent through optical fibers into a bulk-optical (704 nm) and an all-fiber Michelson-interferometer (1310 nm), respectively. The two interferometers are located 35 meters aside from one another. Using Fa...

This work treats degenerate four-wave mixing ~DFWM! in noncentrosymmetric materials, taking into full account the fact that the DFWM signal arises from third-order nonlinear optical effects as well as from two distinct combinations of second-order effects: second-harmonic generation plus difference frequency generation and optical rectification plus Pockels effect. Because of these second order...

We have demonstrated temperature rises that result from nonlinear absorption in single-pass frequencydoubling experiments using femtosecond pulses and a 3-mm-thick KNbO3 crystal. These temperature changes shift the phase-matching curve and must be accounted for to optimize the conversion efficiency. We obtained a maximum second-harmonic generation (SHG) efficiency of 66% at an input power of 10...

The demonstration of a quasi-two-dimensional electron gas (2DEG) in LaAlO3/SrTiO3 heterostructures has stimulated intense research activity in recent years. The 2DEG has unique properties that are promising for applications in all-oxide electronic devices. For such applications it is desirable to have the ability to control 2DEG properties by external stimulus. Here, based on first-principles c...

Nanoparticles of potassium tantalate (KTaO3) and potassium niobate (KNbO3) were synthesized by oxidation of metallic tantalum in molten potassium nitrate with the addition of potassium hydroxide. Magnetization curves obtained on these ferroelectric nanoparticles exhibit a weak ferromagnetism, while these compounds are nonmagnetic in a bulk. The experimental data are used as a start point for th...

The new results are presented of the experimental study of KNbO3 and KTaO3 by means of X-ray photoelectron spectroscopy, soft X-ray emission and X-ray fluorescence spectroscopy. In particular, Nb M4,5 spectra (5p 4f → 3d5/2, 3/2 transition) have been measured over a range of near-threshold excitation energies 206.5 – 240.6 eV, and Ta N3 spectra (5d 6s→ 4p3/2 transition) over 399.4 – 420.4 eV at...

Single-crystalline nanoporous Nb2O5 nanotubes were fabricated by a two-step solution route, the growth of uniform single-crystalline Nb2O5 nanorods and the following ion-assisted selective dissolution along the [001] direction. Nb2O5 tubular structure was created by preferentially etching (001) crystallographic planes, which has a nearly homogeneous diameter and length. Dense nanopores with the...