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1.
We have successfully grown large, high quality LiNbO3 boules in the [0.1·4] direction which lies in the yz plane 38° to the z. Following annealing and poling the material is strain free, striation free and of high optical quality. It has been used to fabricate an electro-optic switch, for second harmonic generation and tunable parametric generation over the 1.4 μm to 4.4 μm spectral range. 相似文献
2.
Summary Microscopic scattering centers in as-grown AgGaS2 were investigated by optical and scanning electron microscopy. The defects consisted of rectangular platelets lying in the
(100) and (010) planes. Their longest dimension (up to 100 μm) was parallel to the [001]-direction. Their shorter dimension
was parallel to the [100] and [010] directions, respectively. The scattering centers were usually fractions of a micrometer
thick and did not appear to have a different composition than the matrix phase according to results by energy-dispersive analysis.
The defects can be eliminated by annealing in Ag2S or quenching from elevated temperature, which suggests that the defects may themselves consist of a two-phase region, part
of which should be Ga2S3-rich, where rodlike or platelike second-phase particles are embedded in the matrix. The quantity and the size of this second
phase make a definitive compositional analysis difficult.
Paper presented at the ?V International Conference on Ternary and Multinary Compounds?, held in Cagliari, September 14–16,
1982. 相似文献
3.
J.A. Freitas Jr. J.G. Tischler N.Y. Garces B.N. Feigelson 《Journal of Crystal Growth》2010,312(18):2564-2568
The structural and optical properties of self-nucleated crystals grown by a near atmospheric pressure solution growth method are presented. High-resolution room temperature Raman scattering studies demonstrate that stress-free crystals with low free-electron background have been produced. Low and room temperature photoluminescence experiments confirm the presence of shallow donors and an unknown shallow acceptor. Large relative intensity variations of the emission bands assigned to recombination process involving donors and acceptor, resulting from significant changes in the incorporation and/or activation of defect associated with each recombination channel, reflect major changes in the intrinsic material properties. 相似文献
4.
Muszkat L Feigelson L Bir L Muszkat KA 《Journal of photochemistry and photobiology. B, Biology》2001,60(1):32-36
The TiO2 photocatalyzed oxidation of the proteins serum albumin, ovalbumin and gamma globulin, is reported. All the amino acids were susceptible to photocatalytic oxidation. However, some were especially vulnerable. Tyrosine was particularly sensitive, as was the semiaromatic histidine, although to a lesser extent. The lack of an activating group on the aromatic ring in Phe, renders the system less amenable to degradation. The photocatalytic degradation of the aliphatic amino acids Gly and Asp, was particularly slow, like in the Fenton oxidation where production of glycine was observed during the cleavage of collagen induced by hydroxyl radicals. Intermediate degradation rate was noticed in Ser, Arg, Val, Cys and Phe. 相似文献
5.
Alex R. Jurgens Kenneth Green Edward R. Ruso Mellard N. Jennings David M. Blum Gregg B. Feigelson 《合成通讯》2013,43(8):1171-1177
An improved scalable procedure for preparation of an α-ketoester acyl anion synthon is described. 相似文献
6.
B.N. Feigelson J.K. HiteN.Y. Garces J.A. Freitas Jr.J.G. Tischler P.B. Klein 《Journal of Crystal Growth》2010,312(18):2551-2557
Near atmospheric pressure solution growth is one of the many developing methods for growing bulk GaN from solution. Apart from other approaches, this method holds certain advantages, such as relatively low growth pressure and temperature, and the ability to grow high quality GaN crystals with different orientations by varying the solvent composition. GaN whiskers of millimeter scale size with exceptional mechanical and optical properties were grown from solution. Crystals of near isotropic shape were also grown from solution by manipulating additives in the basic solvent. 相似文献
7.
Nadolinny V.A. Yelisseyev A.P. Baker J.M. Newton M.E. Twitchen D.J. Hofstaetter A. Feigelson B. 《Hyperfine Interactions》1999,120(1-8):341-345
It is the hyperfine structure of 14N and 13C in the electron paramagnetic resonance (EPR) spectrum which indicates that the unpaired electron of a single substitutional
nitrogen atom in diamond is in one of the four anti-bonding N-C orbitals. We show that, for diamonds containing a very high
concentration of nitrogen, the hyperfine structure of interacting pairs of nitrogen atoms indicates that for close neighbours
there are unique orientations of the constituent N-C bonds, while at larger distances the orientations are random.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
8.
Waveguides formed by incoherent dark solitons 总被引:5,自引:0,他引:5
We demonstrate experimentally optical guidance of coherent light beams, using incoherent light. Such guidance is made possible by generation of partially spatially incoherent self-trapped dark beams (dark incoherent solitons) in a noninstantaneous nonlinear medium. In the one-dimensional case, the incoherent solitons induce single and Y-junction planar waveguides, whereas in the two-dimensional case, they form circular waveguides. These experiments introduce the possibility of controlling high-power laser beams with low-power incoherent light sources such as LED's or lightbulbs. 相似文献
9.
N.Y. Garces B.N. Feigelson J.A. Freitas Jr Jihyun Kim R. Myers-Ward E.R. Glaser 《Journal of Crystal Growth》2010,312(18):2558-2563
The properties of GaN crystals grown from solution at temperatures ranging from 780 to 810 °C and near atmospheric pressure ∼0.14 MPa, have been investigated using low temperature X-band (∼9.5 GHz) electron paramagnetic resonance spectroscopy, micro-Raman spectroscopy, photoluminescense spectroscopy, and photoluminescence imaging. Our samples are spontaneously nucleated thin platelets of approximate dimensions of 2×2×0.025 mm3, or samples grown on both polycrystalline and single crystal HVPE large-area (∼3×8×0.5 mm3) seeds. Electron paramagnetic resonance spectra consists of a single Lorentzian line with axial symmetry about the c-axis, with approximate g-values, g∥=1.951 and g⊥=1.948 and a peak-to-peak linewidth of∼4.0 G. This resonance has been previously assigned to shallow impurity donors/conduction electrons in GaN and attributed to Si- and/or O impurities. Room temperature photoluminescence and photoluminescence imaging data from both Ga- and N-faces show different dominant emission bands, suggesting different incorporation of impurities and/or native defects. Raman scattering and X-ray diffraction show moderate to good crystalline quality. 相似文献