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Second-harmonic generation (SHG) in a lithium niobiate waveguide with ferroelectric domain-reversal grating for quasiphase matching (QPM) provides high theoretical conversion and a manageable guided-mode second harmonic output. However, individual fabrication of the SHG waveguide and the laser diode results in a low probability of satisfying the QPM. A technique for automatically satisfying the QPM conditions may solve this problem. The technique makes use of a Titanium saphire laser and produces a high-efficiency SHG at a third order of the QPM condition.

The interaction of water and carbon dioxide with nanostructured epitaxial (Ba,Sr)TiO3(001) thin film and bulk single crystal SrTiO3(001) surfaces was studied using x-ray photoemission spectroscopy (XPS), thermal desorption spectroscopy (TDS), and density functional theory (DFT). On both surfaces, XPS and TDS indicate D2O and CO2 chemisorb at room temperature with broad thermal desorption peaks (423–723 K) and a peak desorption temperature near 573 K. A comparison of thermal desorption Redhead activation energies to adsorption energies calculated using DFT indicates that defect surface sites are important for the observed strong adsorbate-surface reactivity. Numerical calculations of the competetive adsorption/desorption equilibria for H2O and CO2 on SrTiO3(001) surfaces show that for typical atmospheric concentrations of 0.038% carbon dioxide and 0.247% water vapor the surfaces are covered to a large extent with both adsorbates. The high desorption temperature indicates that these adsorbates have the potential to impact measurements of the electronic structure of BaTiO3–SrTiO3(001) surfaces exposed to air, or prepared in high vacuum deposition systems, as well as the electrical properties of thin film ATiO3-based devices. [ABSTRACT FROM AUTHOR]

The interaction of water and carbon dioxide with nanostructured epitaxial (Ba,Sr)Ti[O.sub.3] (001) thin film and bulk single crystal SrTi[O.sub.3] (001) surfaces is analyzed by using x-ray photoemission spectroscopy (XPS), thermal desorption spectroscopy (TDS) and density functional theory (DFT). The high desorption temperature has shown that the adsorbates might have a major impact on the measurements of the electronic structure of BaTi[O.sub.3]-SrTi[O.sub.3] (001) surfaces exposed to air, or prepared in high vacuum deposition systems, as well as the electrical properties of thin film ATi[O.sub.3]-based devices.

Demonstrates laser emission by photopumping at room temperature from a distributed feedback (DFB) structure for a surface-emitting laser constructed by alternating growths of gallium arsenide and aluminum gallium arsenide multiquantum well. Preparation of the DFB structure; Measurement of the reflectivity spectra of the DFB structure; Results.

Presents a study which demonstrated phase-locked array lasers with large optical waveguide structures. Device structure and design; Characteristic features of the device operation; Conclusion.

Presents a study that developed a waveguide laser diode using a current confinement structure. Design of the device; Features of the laser diode operation; Information on the fabrication of the laser diode.

Presents information on a study which examined the magnesium doping in molecular-beam epitaxy of gallium-arsenic using ionized magnesium beams. Experimental procedures; Results and discussion.

Presents a study that reported the results of photoluminescence measurements on gallium arsenide (GaAs)/Al[sub0.22]Ga[sub0.78]As single quantum wells (QW) inhomogeneously doped with silicon (Si). Low-temperature photoluminescence (PL) due to exciton bound to Si donors; Binding energies of the exciton; Factors which the PL spectra related to impurities in QW depend on.

Studies the effects of thermal annealing on silicon-doped gallium arsenide grown by molecular beam epitaxy. Information on the gallium arsenide layers; Photoluminescence of the layers; Peak intensities of beam epitaxy, carbon and silicon emissions.