We report the displacive and order–disorder characters of PbTiO3 analyzed using a classical atomic model which was developed under the inverse relation between the bond length and the bond valence. The ferroelectric phase changes to the paraelectric phase around 700 K, and the histograms of Ti–O and Pb–O bond lengths have three peaks which become a single peak above the phase transition tempera...

This thesis reports work on passive mode-locking of thulium-doped and erbium-doped fiber ring lasers using the technique of polarization additive pulse mode-locking (PAPM). A self-starting, mode-locked Tm+3-doped fiber laser was demonstrated with 360 to 500 fsec pulses tunable from 1.8 to 1.9 pm, the largest tuning range demonstrated from a rare-earth doped fiber. This laser operated in the sol...

We report on the observation of a multiple-pattern stability region in a photorefractive single-feedback system. Whereas hexagonal patterns are predominant for feedback with positive diffraction length we show that a variety of stable non-hexagonal patterns are generated for certain negative diffraction lengths. For the same values of the control parameters square, rectangular, or squeezed hexa...

Volume holograms recorded in photorefractive materials can find important applications in optical memories and optical computing systems. One problem with a photorefractive hologram is that it gets erased by the readout light. Nondestructive readout can be achieved by hologram fixing, and several fixing methods have been reported. Thermal fixing of holograms was demonstrated in LiNbO3,' Bi1 2Si...

One-dimensional (1D) nanostructures of ternary complex oxides have drawn intensive interest because of their novel size-dependent properties, such as ferroelectric,1a multiferroic,1b and superconductivity.1c Various synthetic approaches, such as aqueous route by employing hydrothermal reaction2 or templates,3 molten-salt synthesis,4 and composite-hydroxide-mediated synthesis5 have been develope...

We demonstrate generation and frequency doubling of unit charge vortices in a linear astigmatic resonator. Topological instability of the double charge harmonic vortices leads to well separated vortex cores that are shown to rotate, and become anisotropic, as the resonator is tuned across resonance. Creation, doubling, and splitting, of vortices in intracavity second harmonic generation2 Optica...

National Center for Nanoscience and Tec [email protected]; [email protected] Institute of Materials Physics and Chem University, Shenyang 110004, China Chemistry Department, Brookhaven Nation USA State Key Laboratory of Advance Technolog Wuhan University of Technology, Wuhan 43 † Electronic supplementary information tables, synthetic procedures, theoretica details for XRD, spectroscopy (XPS, ...

Ceramic perovskite-like oxides with the general formula (A ′ A ′′ . . .)(B ′ B ′′ . . .)O3and titanium-based oxides are of great technological interest because of their large piezoelectric and dielectric response characteristics.[1] In doped and nanoengineered forms, titantium dioxide finds increasing application as an organic and hydrolytic photocatalyst. The binary main-group-metal nitride co...

We produce carrier-envelope-phase-stable 15.7-fs (2-cycle) 740μJ pulses at the 2.1-μm carrier wavelength, from a three-stage optical parametric chirped-pulse amplifier system, pumped by an optically synchronized 49-ps 11-mJ Nd:YLF laser. A novel seed pulse spectral shaping method is used to ascertain the true amplified seed energy and the parametric superfluorescence levels. ©2008 Optical Socie...

We study the anisotropic nature of the Kerr nonlinear response in a beta-barium borate (β -BaB2O4, BBO) nonlinear crystal. The focus is on determining the relevant χ(3) cubic tensor components that affect interaction of type I cascaded second-harmonic generation. Various experiments in the literature are analyzed and we correct the data from some of the experiments for contributions from cascad...