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991.
We propose an efficient scheme to prepare multipartite entanglement of atomic ensembles trapped in separate cavities. Our scheme has high fidelity even with realistic noise based on the repeat-until-success strategy. By employing the quantum memory of the atomic internal state, the scaling efficiency decreases only with the number of atomic ensembles by a slow polynomial law. Moreover, the atomic ensembles also can function as quantum repeaters, which enable our system to compatible with the current experimental technique for quantum communication using atomic ensembles. 相似文献
992.
According to the principle of double-beam interference imaging using an infrared broadband light source, a novel method based on the optical fiber low-coherence Young's interferometer for the measurement of programmable optical fiber delay line is proposed. By measuring the small length increments of delay fiber through the evaluation of the central positions of zero-order interference fringes, we successfully construct a system with a variety of important functions, such as real-time controlling, measurement and displaying. This system offers the benefit that it can be regulated precisely to generate interference stripes once again after the length of fiber segment changes. When the locations of central stripes are moved to coincide with the original markers, the determination of the corresponding fiber optical delay time becomes really simplified, as just by reading out the tinny displacement of the reference arm. Multiple groups of experimental results demonstrate the outstanding performance of the proposed system since it bears a measuring accuracy of μm and a measuring range from 1 mm to 20 cm. 相似文献
993.
A design method along with its results, for a space optical system with high resolution and wide field of view, is described. Such optical systems can be used in the infrared as well as visible configurations. The proposed design is based on an on-axis Ritchey-Chrétien system with corrected lens element while the primary mirror is a segmented aperture. Here the on-axis concept allows wide-field enabling a variety of observations designed for the multi-object spectrometer instruments, optimized for low scattering and low emission of light. The use of segmented mirrors in the optical system allows adopting any method for its fabrication purposes. Segment results are discussed and the image quality of the design based on these results is evaluated in this paper. 相似文献
994.
The ab initio calculations are carried out to investigate the effect of hydrogen, oxygen and nitrogen terminations on the properties of the band edge and the values of the band-gap, as well as the oscillator strength of the silicon nanonets (SiNNs). The oxygen functional groups are found to effectively preserve the direct band-gap nature of the SiNNs, and even change the luminescence properties of the silicon nanowires (SiNWs) to the direct band-gap transition. The appreciable oscillator strength of the first direct transition is obtained for the oxygen terminated nanostructure. The study on the electronic states indicates that the variation of the band edge caused by the surface terminations is attributed to the change of the state compositions. These surface modifications are thought to be useful for silicon band-gap engineering in the area of optoelectronics. 相似文献
995.
Feng JiangHonglie Shen Chao GaoBing Liu Long LinZhou Shen 《Applied Surface Science》2011,257(11):4901-4905
SnS films have been prepared by a novel two-stage process. It involved sputtering of Sn film on glass substrate and sulfurization of the thin metallic tin precursor layers in a vacuum furnace. The X-ray diffraction results showed that the SnS layers had orthorhombic structure and (0 4 0) preferential growth is more and more obvious with the increase of sulfurization time. The SnS film obtained by this work shows high optical absorption efficiency, and the film has a direct optical band gap of about 1.3 eV. The films show p-type conductivity and the resistivity of SnS film decreased obviously under illumination. 相似文献
996.
Hong Wang Rui LiuWei Qiao Jiang Jun ZhuJian Zhi Feng Gui Fu DingXiaolin Zhao 《Applied Surface Science》2011,257(6):2203-2207
Adhesion performance of MEMS materials is increasingly important with the widely use of miniaturized devices. This paper proposed a novel method for improving adhesion performance between electrodeposited Ni multi-layers. The new method is to treat the Ni substrate in nickel chloride plating solution by pulse reverse current technique before electrodeposition. The dense oxide film of Ni substrate can be removed effectively by this electrochemical method, meanwhile, the proper roughness of Ni substrate is in favor of epitaxial growth during electrodeposition. Moreover, the Ni film is electrodeposited by the new method with low stress and coarse crystal grain. Consequently, the adhesion performance of Ni films is improved dramatically. The experimental results show that the adhesion performance of Ni film electrodeposited by the new method is about 3 times that of by traditional method. 相似文献
997.
Baozhu Tian Zhimang Shao Yunfei Ma Jinlong Zhang Feng Chen 《Journal of Physics and Chemistry of Solids》2011,72(11):1290-1295
B-doped together with Ag-loaded mesoporous TiO2 (Ag/B–TiO2) was prepared by a two-step hydrothermal method in the presence of boric acid, triblock copolymer surfactant, and silver nitrate, followed by heat treatment. The obtained samples were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption–desorption. It was revealed that all samples consist of highly crystalline anatase with mesoporous structure. For Ag/B–TiO2, B was doped into TiO2 matrix in the form of both interstitial B and substitutional B while Ag was deposited on the surface of B–TiO2 in the form of metallic silver. Compared with the single B-doped or Ag-loaded TiO2 one, mesoporous Ag/B–TiO2 exhibits much higher visible light photocatalytic activity for the degradation of Rhodamine 6G, which can be ascribed to the synergistic effects of B doping and Ag loading by narrowing the band gap of the photocatalyst and preventing the fast recombination of the photogenerated charge carriers, respectively. 相似文献
998.
Song Dang Jiangbo Yu Lining Sun Jing Feng Hongjie Zhang 《Journal of luminescence》2011,131(9):1857-1863
The ligand 1-(2-naphthyl)-4,4,4-trifluoro-1,3-butanedionate (Htfnd) has been employed to synthesize six novel ternary-lanthanide complexes in which the synergic ligands were 1,10-phenanthroline-5,6-dione (dione) and 4,5-diazafluoren-9-one (dafone), respectively. Two series of complexes Ln(tfnd)3dione and Ln(tfnd)3dafone (Ln=Ho, Pr, Tm) were obtained. These complexes were characterized by elemental analysis, Fourier Transform Infrared spectra and diffused reflectance. After ligand-mediated excitation, Ln(tfnd)3dione and Ln(tfnd)3dafone all show the characteristic NIR luminescence of the corresponding Ln3+ ions (Ln=Ho, Pr, Tm). This can be attributed to the efficient energy transfer from ligands to central Ln3+ ions, via an antenna effect. The indirect energy transfer in the complexes has been investigated and the differences in the luminescence intensity between Ln(tfnd)3dione and Ln(tfnd)3dafone were discussed in detail. The excellent luminescent performances enable these NIR-luminescent complexes to have potential applications in optical amplification operating at 1300 or 1500 nm. 相似文献
999.
Wei Huang Jie-Min Li Li-Mei Yang Zhong-Liang Jin Zheng-Gen Zhong Yu Liu Qin-Ying Chou Feng Li 《Optics & Laser Technology》2011,43(1):214-217
A 32 in RGB LED backlight unit is developed. A local dimming algorithm is designed for the backlight, and grid-noise artifacts in the LC driving signal are successfully removed with consideration of the backlight distribution to provide identical intensity from each LED block. The 32 in RGB LED backlight LCD display has achieved a static display contrast of over 20000:1 and an average power reduction of 30%. We have also obtained the color gamut transformation matrix for transferring a cold cathode fluorescent lamp BLU LCD display gamut system to our RGB LED BLU LCD display gamut system, and extended the color saturation by suppositional color expansion method. As a result, the color has been accurately reproduced in RGB LED BLU LCD display with more richness and more saturation. 相似文献
1000.
The axisymmetrical structural traveling wave cavity (ASSC) CO2 laser is introduced based on the propagation theory of the standing wave cavity CO2 laser. Then the propagation characteristics of the elliptically polarized Gaussian beam are studied in detail. The transforms of the coordinate were used to solve the near field distributions of the output laser beams. The numerical calculations show that the combination of the output beams in the near field can be fulfilled. The diminutive ASSC CO2 laser can be applied into the laser gyro and the measure of the angular velocity. 相似文献