2013
2013
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Record 217 of
Title:Effects of alkaline-earth fluorides and OH- on spectroscopic properties of Yb3+ doped TeO2-ZnO-B2O 3 based glasses
Author(s):Xu, Shennuo(1,2); Wang, Pengfei(1); Zheng, Ruilin(3); Wei, Wei(1,3); Peng, Bo(1,3)Source: Journal of Luminescence Volume: 140 Issue: DOI: 10.1016/j.jlumin.2013.02.056 Published: 2013Abstract:New kinds of Yb2O3-doped boro-tellurite (TeO 2-ZnO-B2O3) based glasses were prepared by introducing alkaline-earth fluorides (MgF2, CaF2, SrF 2, and BaF2). Their structural and spectroscopic properties were investigated by Raman and absorption spectra measurements. Dehydration ability of alkaline-earth fluorides was studied. The OH can have an obvious effect on fluorescence lifetime of Yb3+, when OH concentration is higher than NOH=4.66×1019 cm -3. For TeO2-ZnO-B2O3-BaF 2 glass system, the peak values of integrated absorption and emission cross-sections achieve 7.44×104 pm3 and 1.416 pm2, respectively. It indicates that the Yb3+-doped boro-tellurite glasses containing alkaline-earth fluorides are potential materials for waveguide laser, and optical amplifier. ? 2013 Elsevier B.V.Accession Number: 20131516184347 -
Record 218 of
Title:Passively harmonic mode locking in ytterbium-doped fiber laser with graphene oxide saturable absorber
Author(s):Li, Huiquan(1); Wang, Yonggang(2); Yan, Peiguang(1); Cao, Guangzhong(3); Zhao, Junqing(1); Zhang, Gelin(1); Huang, Shisheng(1); Lin, Rongyong(1)Source: Optical Engineering Volume: 52 Issue: 12 DOI: 10.1117/1.OE.52.12.126102 Published: December 2013Abstract:We have demonstrated the dissipative solitons generated in an ytterbium-doped fiber laser cavity using graphene oxide as the saturable absorber. The lasing light, centered at 1077.2 nm, has a 3 dB spectral bandwidth of ～1.12 nm. Under different launched pump powers and appropriate polarization orientations, harmonic mode-locked of second- and third-order pulse trains have been achieved; the corresponding 3-dB bandwidth and pulse duration have been detected. ? The Authors. Published by SPIE.Accession Number: 20135117117182 -
Record 219 of
Title:Focal length testing method of long focal length laser optical system
Author(s):Duan, Yaxuan(1); Chen, Yongquan(1); Zhao, Jianke(1); Li, Kun(1); Tian, Liude(1); Zhang, Jie(1)Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 40 Issue: 4 DOI: 10.3788/CJL201340.0408005 Published: April 2013Abstract:In order to measure the focal length of long focal length laser optical system, a method based on the principle of autocollimation, using fiber laser, beam splitter, flat mirror, precision angular instrument, charge couple device (CCD) and wavefront sensor is proposed. The fiber pinhole is placed at the focal point of laser optical system by testing the transmission wavefront of laser optical system with the Shack-Hartmann wavefront. Then, the CCD is placed at the best image surface by the scanning focus algorithm. The synchronization acquisition of the angular instrument and CCD is made. The focal length of laser optical system is calculated with the angle got by precision angular instrument and the deviation of pinhole image calculated by the centroid algorithm. The long focal length laser optical system of which the focal length is 7171 mm has been tested by this method. The uncertainty of test result is 13.48 mm (k=2). The test results show that this method is practical to the focal length testing of long focal length laser optical system.Accession Number: 20132216376023 -
Record 220 of
Title:Measurement of transmittance for highly transparent liquid
Author(s):Wang, Jian(1,2,3); Wei, Jian-Ping(3); Yang, Bo(4); Gao, Zhi-Yang(4); Yang, Xue-Feng(1)Source: Guangxue Jingmi Gongcheng/Optics and Precision Engineering Volume: 21 Issue: 3 DOI: 10.3788/OPE.20132103.0624 Published: March 2013Abstract:This paper analyzes the reasons that the mistaken transmittance results are prone to occur in a highly transparent liquid measurement by employing a visible spectrophotometer in traditional methods. On the basis of the analysis results, two kinds of simple ways for measuring the transmittance of highly transparent liquid are proposed. One way is to fit both kinds of transparent faces of a colorimetric ware closely together, in which the film is formed with the pending liquid to be tested. This structure is known as the "liquid film reference cell". The other way is to fit the pending liquid into a 1 cm length colorimetric ware as the reference cell, and fill the pending liquid into a 2 cm length colorimetric ware as the sample cell. With the two methods, several kinds of common liquids are measured and almost identical results are obtained. Measurements show that the transmittances of measured liquids such as alcohol, water are all in 98%~100% at the visible light range. These ways eliminate the mistaken transmittance results and provide effective methods for the measurement of transparent liquid.Accession Number: 20131616213808 -
Record 221 of
Title:Local tomography based on grey model
Author(s):Ye, Renzhen(1); Lu, Xiaoqiang(2); Liu, Haihua(3)Source: Neurocomputing Volume: 101 Issue: DOI: 10.1016/j.neucom.2012.06.006 Published: February 4, 2013Abstract:This paper studied region-of-interest (ROI) problem of computed tomography. It is necessary to use almost local projection data to reduce radiation exposure or time in medical imaging when only a small part of the patient's body needs to be viewed. Improving the quality of reconstructed ROI and reducing radiation exposure are our aims. However, the traditional local tomography algorithm has difficulty in reconstructing the ROI due to significant truncation artifacts. In this paper, a new grey model based method is reported for ROI image reconstruction from truncated projection data. By using grey model, the proposed method can extrapolate the truncated projection data, and reconstruct the ROI from a set of its projections. As a result, about 75% of full projection data are saved, as compared with other traditional approachs, in reconstructing a local region of 32 pixels in radius in an image of 256×256 pixels. Experimental results show that the proposed method exhibits more saving in exposure as compared with other local tomography algorithms and results in better quality of the reconstructed image. ? 2012 Elsevier B.V.Accession Number: 20124615668506 -
Record 222 of
Title:Two-photon absorption photochromic optical image storage in indoly-benzylfulgimide/PMMA film
Author(s):Sun, Xiaoman(1); Menke, Neimule(1,2); Yao, Baoli(3); Lei, Ming(3); Wang, Yingli(3); Chao, Lumen(1); Chen, Yi(4)Source: Advanced Materials Research Volume: 660 Issue: DOI: 10.4028/www.scientific.net/AMR.660.10 Published: 2013Abstract:As one kind of organic photochromic optical storage material, fulgides are well-known for their thermally irreversibility. The two-photon absorption 3D optical storage technology is one of the hot research topics in the field of high-density information storage. Using optical image storage technology the recording and reading rates can be improved. In this paper, it's found that in one kind of 3-indoly-benzylfulgimide/PMMA film, there exits two-photon absorption property. And depending on this property, the two-photon absorption photochromic optical image storage was realized in an indoly-benzylfulgimide/PMMA film. It is proved that the N-benzyl-1,3,4-trimethyl-2- (2-methyl-) indoly-fulgimide has potential application in the two-photon absorption 3D optical storage. ? (2013) Trans Tech Publications, Switzerland.Accession Number: 20131116108214 -
Record 223 of
Title:Research progress of microstructured polymer optical fiber preparation method
Author(s):Wang, Jian(1,2,3); Wei, Jian-Ping(1); Yang, Bo(4); Zhang, Li-Wei(3); Yang, Xue-Feng(3); Yuan, Xiao-Li(3)Source: Gongneng Cailiao/Journal of Functional Materials Volume: 44 Issue: SUPPL.2 DOI: Published: December 30, 2013Abstract:Microstructured optical fibers attract extensive attention for their excellent optical properties. As an important part of the microstructure fiber, microstructured polymer optical fibers have been studied in depth by researchers. In this paper, the preparation methods of microstructured polymer fiber preform are reviewed. It mainly introduces the methods such as packing method, drilling holes method, casting method, extrusion method and extrusion-molding method. The advantages and disadvantages of these methods are analyzed and prospected.Accession Number: 20140817350390 -
Record 224 of
Title:Robust probabilistic tensor analysis for time-variant collaborative filtering
Author(s):Pan, Jing(1); Ma, Zhao(2); Pang, Yanwei(2); Yuan, Yuan(3)Source: Neurocomputing Volume: 119 Issue: DOI: 10.1016/j.neucom.2012.03.035 Published: November 7, 2013Abstract:The input data of collaborative filtering, also known as recommendation system, are usually sparse and noisy. In addition, in many cases the data are time-variant and have obvious periodic property. In this paper, we take the two characteristics into account. To utilize the time-variant and periodic properties, we describe the data as a three-order tensor and then formulate the collaborative filtering as a problem of probabilistic tensor decomposition with a time-periodical constraint. The robustness is achieved by employing Tsallis divergence to describe the objective function and q-EM algorithm to find the optimal solution. The proposed method is demonstrated on movie recommendation. Experimental results on two Netflix and Movielens databases show the superiority of the proposed method. ? 2012 Elsevier B.V.Accession Number: 20133416640450 -
Record 225 of
Title:Resolutiesolution performance of the extra ultraviolet telescopes
Author(s):Fu, Huai yang(1); Zhou, Si Zhong(1); Jiang, Kai(1); Mei, Chao(1)Source: Nanophotonics, Nanoelectronics and Nanosensor, N3 2013 Volume: Issue: DOI: Published: 2013Abstract:The Extreme Ultraviolet Telescopes (EUT) Operates at wavelengths between 100-1000 ?. As an important parameter of the telescope system, before the launch, angular resolution is necessary to be calibrated for testing the imaging performance of EUT. However, the difficulty and expense of fabricating optical testing systems capable of imaging the characteristic EUV wavelengths, has precluded in working wavelength resolution testing. This article taken a Ritchey-Chrétien normal incidence optical system as sample and resolution tests were carried out at visible wavelength. Based on this measurement, the angular resolution error budget at visible wavelength was calculated. At working wavelength, we added the squares of the pointing jitter error, the resolution focusing error and the scattering error, to the theoretical Rayleigh diffraction limit at the wavelength of operation, and then take the square root of this sum, an upper limit estimate of telescope's resolution was obtained about 0.4705 arcsec. This result proved that the EUT worked at diffraction-limited level and the resolution performance has met the demand of design. ? OSA 2013.Accession Number: 20134717010618 -
Record 226 of
Title:Optical system design of polarization imaging spectrometer for ground-based astronomical observation
Author(s):Chang, Ling-Ying(1); Yao, Da-Wei(2); Zhao, Bao-Chang(2); Qiu, Yue-Hong(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8910 Issue: DOI: 10.1117/12.2034993 Published: 2013Abstract:With the development of astrophysics, the astrophysics demands are higher and higher. Astronomical spectral polarization observation can obtain more object information to provide comprehensive data for further research. A polarization imaging spectrometer based on acousto-optic tunable filter was developed for ground-based telescope, which can obtain the image spectral polarization information at the same time. In this paper, first, the work principle of AOTF was introduced, then described the AOTF imaging system for ground-based astronomical observation, it covers the spectral band from 450nm to 900nm. The device can provide about 3.6° view field angle and 10mm aperture, which included TeO2 crystal, image optical system, a charged coupled device(CCD)camera, rf electronics and control and processing software. Finally the paper presented the results of optical design. ? 2013 SPIE.Accession Number: 20141317516412 -
Record 227 of
Title:Design of hybrid refractive-diffractive visible lens with small F-number
Author(s):Wang, Hu(1,2); Luo, Jianjun(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8910 Issue: DOI: 10.1117/12.2032432 Published: 2013Abstract:A hybrid diffractive/refractive visible lens with small F-number of 1.5 is proposed based on the special chromatic aberration of diffractive optical element. It is used in the optical system of visible camera for space debris. The visible lens has an effective focal length of 100 mm, a working wavelength range of 0.5-0.8μm and a field of view 6°. Firstly, the lens system consists of three groups and five lenses. Then, aspheric and diffractive surfaces are used in order to correct high-order aberrations resulting from large relative aperture. Finally, the lens is designed with the help of Code-v optical design software. The lens is evaluated by energy concentration, the dispersion spot diameter, lateral color, distortion, the simulated final design shows adequate image quality. The method puts forward a new ideas for visible camera for space debris optical system design and had an important reference significance and application value. ? 2013 SPIE.Accession Number: 20141317516360 -
Record 228 of
Title:Optical system design of visible camera for space debris
Author(s):Wang, Hu(1,2); Luo, Jianjun(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8910 Issue: DOI: 10.1117/12.2032431 Published: 2013Abstract:In order to detect the space debris, a visible camera for space debris was proposed. The visible camera was mainly consisted of primary mirror, secondary mirror. In order to balance aberration, six correcting lens were used in the optical system. To reduce the visible camera system size, two mirrors were joined, which could fold the system and shorten the overall length. The focal length was 12000 mm, field of view was 1. 0 and the f-number was 10.0. The imaging quafity of the optical system in visible camera approached to diffraction limit. ? 2013 SPIE.Accession Number: 20141317516359