2010
2010
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Record 265 of
Title:Growth and properties of conductive substrates of ultraviolet photocathode with high resistance
Author(s):Zhao, Feifei(1,2); Zhao, Baosheng(1); Wei, Yonglin(1); Zhang, Xinghua(1,2); Sai, Xiaofeng(1); Zou, Wei(1)Source: Guangxue Xuebao/Acta Optica Sinica Volume: 30 Issue: 4 DOI: 10.3788/AOS20103004.1211 Published: April 2010Abstract:Tin-doped indium oxide (ITO) conductive thin film is prepared on MgF2 substrate by electron beam evaporation. The effect of oxygen and annealing on the sheet resistance and ultraviolet (UV) transmittance of ITO film is investigated. Furthermore, the properties of ITO film are compared with conventional conductive film substrates Au and Cr. The surface morphological image, sheet resistance, microstructure and transmittance curves in the wave band of 190~800 nm are investigated by optical microscope (OM), four-probe method, high resistance meter, X-ray diffractomer (XRD) and spectrophotometer. Variation range of transmittance is acquired in the wave band of 200~400 nm when the sheet resistance reaches 107 Ω. The results indicate that the sheet resistance of thin film prepared with oxygen is higher than that without oxygen; after annealing the sheet resistance of thin film decreases and the microstructure changes from amorphous to polycrystalline. Compared to Au and Cr, the average transmittance of ITO film with the same sheet resistance of 107 Ω or so, which is prepared with oxygen and annealing, is 10% higher in the wave band of 200~400 nm.Accession Number: 20102112958592 -
Record 266 of
Title:A review of active appearance models
Author(s):Gao, Xinbo(1); Su, Ya(1); Li, Xuelong(2); Tao, Dacheng(3)Source: IEEE Transactions on Systems, Man and Cybernetics Part C: Applications and Reviews Volume: 40 Issue: 2 DOI: 10.1109/TSMCC.2009.2035631 Published: March 2010Abstract:Active appearance model (AAM) is a powerful generative method for modeling deformable objects. The model decouples the shape and the texture variations of objects, which is followed by an efficient gradient-based model fitting method. Due to the flexible and simple framework, AAM has been widely applied in the fields of computer vision. However, difficulties are met when it is applied to various practical issues, which lead to a lot of prominent improvements to the model. Nevertheless, these difficulties and improvements have not been studied systematically. This motivates us to review the recent advances of AAM. This paper focuses on the improvements in the literature in turns of the problems suffered by AAM in practical applications. Therefore, these algorithms are summarized from three aspects, i.e., efficiency, discrimination, and robustness. Additionally, some applications and implementations of AAM are also enumerated. The main purpose of this paper is to serve as a guide for further research. ? 2009 IEEE.Accession Number: 20100912737263 -
Record 267 of
Title:High birefringent rhombic-hole photonic crystal fibers
Author(s):Hu, Bin(1,2); Lu, Min(1); Li, Weinan(1); Zou, Kuaisheng(1); Zhou, Zhiguang(1,2); Lin, Aoxiang(1); Li, Ning(1,2)Source: Applied Optics Volume: 49 Issue: 31 DOI: 10.1364/AO.49.006098 Published: November 1, 2010Abstract:High birefringence induced by rhombic air-hole photonic crystal fibers (PCFs) is numerically analyzed by using the finite-element method. The birefringence of a few kinds of PCFs was investigated with different parameters related to rhombic holes, including the rhombic-hole shape, size, and spacing. It was found that the birefringence of the proposed rhombic-hole PCF in this study is relatively larger than that of an elliptical-hole PCF with the same air-filling fraction (f = 0.0375) when the ratio of the rhombic-hole diagonal length is equal to the elliptical-hole ellipticity. ? 2010 Optical Society of America.Accession Number: 20104613389158 -
Record 268 of
Title:Transmission characteristics of two-cavity Fabry-Perot structure
Author(s):Chen, Mingrui(1,2); Bi, Siwen(1); Dou, Xibo(1,2)Source: Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams Volume: 22 Issue: 8 DOI: 10.3788/HPLPB20102208.1870 Published: August 2010Abstract:A two-cavity Fabry-Perot(F-P) structure is compared to the conventional F-P structure. The characteristics of transmission spectra for the conventional and the two-cavity F-P structures are theoretically analyzed. Based on the theoretical analysis, the transmission spectra of conventional, symmetric and asymmetric two-cavity F-P structures are simulated, and the results are discussed. The results show that, while the increase of the cavity length of a conventional F-P structure results in multiple resonant peaks on both sides of the main peak, the two-cavity F-P structures of the same total length can improve spectral range effectively and keep the main peak without degrading the performance through proper design of the mirror reflectivity and cavity lengths. The mirror reflectivity also decides the full width at half maximum(FWHM) of the peaks at the central wavelength for both conventional and two-cavity F-P structures. The influences of cavity lengths and their ratio, and mirror reflectivity on transmissivity, FWHM and spectral range of the two-cavity F-P structure have been discussed.Accession Number: 20103413174859 -
Record 269 of
Title:Dispersion measurement of Yb-doped fiber by a spectral interferometric technique
Author(s):Zhang, Ting(1,2); Yang, Zhi(1); Zhao, Wei(1); Wang, Yishan(1); Fang, Ping(1,2); Li, Cheng(1)Source: Chinese Optics Letters Volume: 8 Issue: 3 DOI: 10.3788/COL20100803.0262 Published: March 2010Abstract:The dispersion of Yb-doped fiber is measured by a spectral interferometric technique. The experimental verification is achieved by comparing the measured data with published data of the Nufern 1060xp fiber and the measurement relative error is 1.36%. The parameters of the experimental system, such as minimum required source bandwidth and minimum fiber length, are introduced and analyzed in the measurement. The minimum required source bandwidth predicted through theoretical calculation at the center wavelength of 1070 nm is 19.3 nm, which perfectly agrees with the experimental value. ? 2010 Chinese Optics Latters.Accession Number: 20101912923172 -
Record 270 of
Title:Subspace Learning
Author(s):Li, Xuelong(1); Tao, Dacheng(2)Source: Neurocomputing Volume: 73 Issue: 10-12 DOI: 10.1016/j.neucom.2010.02.012 Published: June 2010Abstract:nullAccession Number: 20102112950554 -
Record 271 of
Title:Fabrication of micro devices by use of optical tweezers
Author(s):Peng, Fei(1,2); Yao, Baoli(1); Lei, Ming(1); Yan, Shaohui(1); Zhao, Wei(1)Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 37 Issue: 5 DOI: 10.3788/CJL20103705.1245 Published: May 2010Abstract:Optical tweezers, as a powerful tool of manipulation of micro-objects, is commonly used for trapping micro-objects and controlling their movement. Making use of the highly focused heat energy at the laser focus and the transportation ability of the optical tweezers, the process of crystallization, the shape of crystal separating out from solution, and the arrangement mode of the deposition from precipitation reaction can be controlled precisely, which may be used as a means of making micro devices. The laser-induced crystallization method and the laser-assisted precipitation method are used to make micro devices with the copper sulfate and the calcium carbonate as the based materials, respectively. Different factors influencing grow speed of crystals are investigated. The condition of precipitation reaction fitting to the laser-assisted precipitation method is discussed. By comparing, the method of laser-induced crystallization works more efficiently, while the method of laser-assisted precipitation can produce more stable devices. The experimental equipment and the proposed methods not only spread the application domain of optical tweezers but also provide a new way for fabrication of micro devices.Accession Number: 20102413003969 -
Record 272 of
Title:A single photon counting detector based on one-dimensional Vernier anode
Author(s):Yang, Hao(1,2); Zhao, Bao-Sheng(1); Sheng, Li-Zhi(1); Li, Mei(1,2); Yan, Qiu-Rong(1); Liu, Yong-An(1)Source: Chinese Physics Letters Volume: 27 Issue: 5 DOI: 10.1088/0256-307X/27/5/058501 Published: 2010Abstract:The mathematical expression on decoding the one-dimensional (1D) Vernier anode is deduced theoretically, and the corresponding 1D-Vernier anode collector is developed. A photon counting imaging and detection system is constructed based on a 1D-Vernier anode detector and electronic readout subsystem. With wavelengths of 253.7 nm from the mercury lamp as the ultraviolet emission source, the spatial resolution of the prototype is proved to be better than 100μm along the x-direction in experiment. ? 2010 Chinese Physical Society and IOP Publishing Ltd.Accession Number: 20220711660231 -
Record 273 of
Title:Vectorial structure of a hard-edged-diffracted four-petal Gaussian beam in the far field
Author(s):Long, Xuewen(1,2); Lu, Keqing(1); Zhang, Yuhong(1,2); Guo, Jianbang(1,2); Li, Kehao(1,2)Source: Optics Communications Volume: 283 Issue: 23 DOI: 10.1016/j.optcom.2010.06.097 Published: December 1, 2010Abstract:Based on the vector angular spectrum method and the stationary phase method and the fact that a circular aperture function can be expanded into a finite sum of complex Gaussian functions, the analytical vectorial structure of a four-petal Gaussian beam (FPGB) diffracted by a circular aperture is derived in the far field. The energy flux distributions and the diffraction effect introduced by the aperture are studied and illustrated graphically. Moreover, the influence of the f-parameter and the truncation parameter on the non-paraxiality is demonstrated in detail. In addition, the approximate formulas obtained in this paper can degenerate into un-apertured case when the truncation parameter tends to infinity. This work is beneficial to strengthen the understanding of vectorial properties of the FPGB diffracted by a circular aperture. ? 2010 Elsevier B.V. All rights reserved.Accession Number: 20104113287814 -
Record 274 of
Title:Effect of vectorial nature on spectral anomalies of ultrashort pulsed beams from a hard-edged aperture
Author(s):Yang, Y.(1); Duan, K.(2); Jiang, D.(1); Zhang, J.(1); Chen, Y.(1)Source: Applied Physics B: Lasers and Optics Volume: 98 Issue: 1 DOI: 10.1007/s00340-009-3730-6 Published: January 2010Abstract:Based on the vectorial Rayleigh-Sommerfeld diffraction integrals, the analytical expression for the spectral intensity of a vectorial nonparaxial ultrashort pulsed Gaussian beam diffracted at a rectangular hard-aperture is derived. The results of the far-field and paraxial cases can be regarded as special cases of the general expression. Effect of vectorial nature on spectral anomalies of ultrashort pulsed beams passing through a hard-edged aperture is analyzed in detail. It is shown that the spectral switch near the phase singularity, which is predicated under the condition of the scalar paraxial theory, disappears with the increasing effect of the vectorial and nonparaxial nature. ? 2009 Springer-Verlag.Accession Number: 20095012539462 -
Record 275 of
Title:Influence of driving mode on the operation stability of organic light-emitting diodes
Author(s):Zhang, W.(1); Wu, Z.(2); Zhang, X.(2); Liang, S.(2); Jiao, B.(2); Hou, X.(1,2)Source: Optoelectronics and Advanced Materials, Rapid Communications Volume: 4 Issue: 9 DOI: Published: 2010Abstract:The influence of pulse current (PC) versus direct current (DC) driving mode on the operation stability of organic light-emitting diodes, which based on N,N′-di(naphthalene-1-yl)-N,N′-diphenylbenzidine (NPB) and tris(8-hydroxyquinoline) aluminum (Alq3) without hole-injection layer (HIL) and with two different HILs, was investigated. The two HILs were copper phthalocyanine (CuPc) and 4,4′,4″-tris(3-methylphenylphenylamino) triphenylamine (m-MDTATA) respectively. It was found that the lifetimes of devices without HIL and with CuPc, m-MTDATA as the HIL under PC driving mode were 2, 1.5 and 0.9 times longer than that under DC driving mode respectively. Analysis of electrical characteristics of corresponding hole-only devices showed that the injected holes into device were greatly reduced by inserting m-MTDATA layer compared to the two other devices, and indicated that different ratios of the injected electrons/holes were obtained in these devices, which play a dominant role in the influence of driving mode on the operation stability.Accession Number: 20203409076436 -
Record 276 of
Title:Deterministic column-based matrix decomposition
Author(s):Li, Xuelong(1); Pang, Yawei(2)Source: IEEE Transactions on Knowledge and Data Engineering Volume: 22 Issue: 1 DOI: 10.1109/TKDE.2009.64 Published: January 2010Abstract:In this paper, we propose a deterministic column-based matrix decomposition method. Conventional column-based matrix decomposition (CX) computes the columns by randomly sampling columns of the data matrix. Instead, the newly proposed method (termed as CX-D) selects columns in a deterministic manner, which well approximates singular value decomposition. The experimental results well demonstrate the power and the advantages of the proposed method upon three real-world data sets. ? 2006 IEEE.Accession Number: 20100112606902