-
Record 337 of
Title:Study on 2.0 μm fluorescence of Ho-doped water-free fluorotellurite glasses
Author(s):He, Jianli(1,2); Zhan, Huan(1,2); Zhou, Zhiguang(1); Zhang, Aidong(1); Lin, Aoxiang(1)
Source: Optical Materials Volume: 35 Issue: 12 DOI: 10.1016/j.optmat.2013.07.031 Published: October 2013
Abstract:Ho3+-doped water-free fluorotellurite glasses with composition of 60TeO2-30ZnF2-10NaF (mol%, TZNF60) were made by using specially-designed physical and chemical dehydration technique. 2.04 μm fluorescence (Ho3+: 5I7 → 5I8) was observed experimentally and presented in this paper: A broad bandwidth of ～149 nm, large simulated emission cross-section of 7.2 × 10-21 cm2, and the longest reported fluorescence lifetime of ～10 ms among all the reported Ho3+-doped oxide glasses. Thanks to the absence of OH groups and low phonon energy with the addition fluorides into tellurite oxide glasses, 1.00Ho-TZNF60 glass demonstrates the maximum figure of merit (σem × τf) of 7.13 × 10-27 m2 s, thus regarded as a promising optical material for the development of 2.0 μm fiber lasers. ? 2013 Elsevier B.V. All rights reserved.
Accession Number: 20134116840965
-
Record 338 of
Title:Graph-regularized low-rank representation for destriping of hyperspectral images
Author(s):Lu, Xiaoqiang(1); Wang, Yulong(2); Yuan, Yuan(1)
Source: IEEE Transactions on Geoscience and Remote Sensing Volume: 51 Issue: 7 DOI: 10.1109/TGRS.2012.2226730 Published: 2013
Abstract:Hyperspectral image destriping is a challenging and promising theme in remote sensing. Striping noise is a ubiquitous phenomenon in hyperspectral imagery, which may severely degrade the visual quality. A variety of methods have been proposed to effectively alleviate the effects of the striping noise. However, most of them fail to take full advantage of the high spectral correlation between the observation subimages in distinct bands and consider the local manifold structure of the hyperspectral data space. In order to remedy this drawback, in this paper, a novel graph-regularized low-rank representation (LRR) destriping algorithm is proposed by incorporating the LRR technique. To obtain desired destriping performance, two sides of performing destriping are included: 1) To exploit the high spectral correlation between the observation subimages in distinct bands, the technique of LRR is first utilized for destriping, and 2) to preserve the intrinsic local structure of the original hyperspectral data, the graph regularizer is incorporated in the objective function. The experimental results and quantitative analysis demonstrate that the proposed method can both remove striping noise and achieve cleaner and higher contrast reconstructed results. ? 1980-2012 IEEE.
Accession Number: 20132916512171
-
Record 339 of
Title:Mid-infrared fluorotellurite glasses and fibers
Author(s):Zhan, Huan(1,2); Zhang, Aidong(1); He, Jianli(1,2); Zhou, Zhiguang(1); Li, Lu(1,2); Lin, Aoxiang(1)
Source: CLEO: Applications and Technology, CLEO_AT 2013 Volume: Issue: DOI: Published: 2013
Abstract:Abstract: We report on the fabrication and characterization of rare earth ions-doped water-free fluorotellurite glasses and fibers. For 2.8 mm glass fiber rods, its background loss was ~12 dB/m in the range of 2.5~4.2 μm. ? OSA 2013.
Accession Number: 20134717001741
-
Record 340 of
Title:Broadband, low-loss, dispersion flattened porous-core photonic bandgap fiber for terahertz (THz)-wave propagation
Author(s):Liang, Jian(1); Ren, Liyong(1); Chen, Nana(1); Zhou, Changhe(2)
Source: Optics Communications Volume: 295 Issue: DOI: 10.1016/j.optcom.2013.01.010 Published: May 15, 2013
Abstract:By intentionally combining the porous fiber and the air-core photonic bandgap fiber, a kind of porous-core photonic bandgap fiber for guiding terahertz (THz) wave is proposed in this paper. THz wave in a frequency range from 0.98 THz to 1.15 THz can be well concentrated in the fiber core region with a low loss. Compared with the air-core photonic bandgap fiber, this kind of fiber can also provide a broader bandwidth and a much more flattened dispersion. Numerical simulations are performed by the plane wave expansion method and the finite element method. ? 2013 Elsevier B.V.
Accession Number: 20131416168166
-
Record 341 of
Title:Investigation of mid-IR luminescence properties and energy transfer in Dy3+-doped and Dy3+, Tm3+-codoped chalcohalide glasses
Author(s):Meng, Wei(1,2); Xu, Yantao(1); Guo, Haitao(1); Lu, Chunfeng(1); Hou, Chaoqi(1); Lu, Min(1); Wang, Pengfei(1); Li, Weinan(1); Peng, Bo(1); Lu, Yunqing(2); Wei, Wei(1,2)
Source: Optical Materials Volume: 35 Issue: 8 DOI: 10.1016/j.optmat.2013.03.007 Published: June 2013
Abstract:A series of Dy3+-doped and Dy3+/Tm 3+-codoped chalcohalide glasses (72GeS2·18Ga 2S3·10AgI) were prepared. The optical properties of the glasses, including Judd-Ofelt strength parameters, transition probabilities, excited state lifetimes, fluorescence branching ratios and emission cross-sections were calculated based on the absorption and emission spectra. For the Dy3+-doped glasses, the emission intensity at 1330 nm increases obviously with increasing of Dy3+ doping content from 0.2 to 0.5 wt.%, and the fluorescence lifetimes keep at 40 μs. The emission cross-section of the Dy3+-doped glass (0.5 wt.%) was calculated to be 4.16 × 10-20 cm2. For the Dy3+/Tm 3+-codoped glasses, Tm3+ ions can absorb excitation energy and effectively transfer energy to Dy3+ ions. The intensified mid-IR emissions were observed obviously, the emission cross-sections for the codoped glasses (0.8 wt.% Dy3+ and 0.5 wt.% Tm3+) were calculated to be 1.40 × 10-20 cm2 at 2900 nm and 1.52 × 10-20 cm2 at 4300 nm, respectively. ? 2013 Elsevier B.V. All rights reserved.
Accession Number: 20132316393157
-
Record 342 of
Title:Enhanced luminescence properties of monodisperse trioctylphosphine oxide-capped Nd3+-doped LaF3 nanorods without OH groups
Author(s):Cui, Xiaoxia(1); Guo, Haitao(1); Hou, Chaoqi(1); Gao, Fei(1); Wang, Zhongyue(2); Wei, Wei(1,2); Peng, Bo(1,2)
Source: Colloids and Surfaces A: Physicochemical and Engineering Aspects Volume: 436 Issue: DOI: 10.1016/j.colsurfa.2013.07.009 Published: September 5, 2013
Abstract:Nd3+-doped LaF3 nanorods without -OH groups were synthesized via a simple thermolysis method in trioctylphosphine oxide (TOPO) solvent. FTIR spectrum indicates that TOPO molecules have been coordinated to LaF3:Nd nanorods surface, which reduce the number of -OH groups on the nanoparticles surface effectively. The structure and morphology of as-synthesized nanorods were characterized. The possible grow mechanism of LaF3:Nd nanorods has been also discussed in detail. The TOPO capped LaF3:Nd nanoparticles preferentially grow along the orientation under high temperature. Based on the absorption spectra and Judd-Ofelt theory, higher value of emission cross-section for 4F3/2→4I11/2 transition of Nd3+ was calculated to be 3.22×10-20cm2. The strong fluorescence intensity of LaF3:Nd nanorods in chloroform demonstrates that these nanorods are promising luminescence materials. ? 2013 Elsevier B.V.
Accession Number: 20133316611695
-
Record 343 of
Title:Solid-state YVO4/Nd:YVO4/KTP green laser system for the generation of subnanosecond pulses with adjustable kilohertz repetition rate
Author(s):Zhang, Haijuan(1); Zhao, Shengzhi(1); Yang, Kejian(1); Li, Guiqiu(1); Li, Dechun(1); Zhao, Jia(1); Wang, Yonggang(2)
Source: Applied Optics Volume: 52 Issue: 27 DOI: 10.1364/AO.52.006776 Published: September 20, 2013
Abstract:A solid-state green laser generating subnanosecond pulses with adjustable kilohertz repetition rate is presented. This pulse laser system is composed of a Q-switched and mode-locked YVO4/Nd:YVO4/KTP laser simultaneously modulated by an electro-optic (EO) modulator and a central semiconductor saturable absorption mirror. Because the repetition rate of the Q-switched envelope in this laser depends on the modulation frequency of the EO modulator, so long as the pulsewidth of the Q-switched envelope is shorter than the cavity roundtrip transmit time, i.e., the time interval of two neighboring mode-locking pulses, only one mode-locking pulse exists underneath a Q-switched envelope, resulting in the generation of subnanosecond pulses with kilohertz repetition rate. The experimental results show that the pulsewidth of subnanosecond pulses decreases with increasing pump power and the shortest pulse generated at 1 kHz was 450 ps with pulse energy as high as 252 μJ, corresponding to a peak power of 560 kW. In addition, this laser was confirmed to have high stability, and the pulse repetition rate could be freely adjusted from 1 to 4 kHz. ? 2013 Optical Society of America.
Accession Number: 20134016803265
-
Record 344 of
Title:Synthesis and optical properties of neodymium-doped lanthanum fluoride nano-laser materials
Author(s):Cui, Xiaoxia(1); Gao, Fei(1); Hou, Chaoqi(1); Guo, Haitao(1); Wang, Zhongyue(2); Wei, Wei(1,2); Peng, Bo(1,2)
Source: Zhongguo Jiguang/Chinese Journal of Lasers Volume: 40 Issue: 6 DOI: 10.3788/CJL201340.0606003 Published: June 2013
Abstract:A new type of neodymium-doped lanthanum fluoride (LaF3:Nd) nanoparticles are synthesized by hydrothermal method. It exhibits hexagonal structure and a size of about 25 nm. A series of different concentrations of LaF3:Nd nanoparticles dispersion are prepared by ultrasonic technology. The visible-near-infrared spectra show that the dispersion with the optical path of 5 mm and neodymium ion concentration of 1×1020 cm-3 shows high transmittance of 85% at 1053 nm. The lifetime of the La0.95Nd0.05F3 nanoparticles dispersion is 200 μs, compared with that of the powder, it is reduced by 3.8%. These results indicate that the LaF3:Nd nanoparticles dispersion with low fluorescence quenching rate, high ion concentration and high transmittance is a kind of promising material used for high repetition rate, high-power and ultra short pulse liquid laser.
Accession Number: 20133516678864
-
Record 345 of
Title:Simulative study of optical pulse propagation in water based on Fournier-Forand and Henyey-Greenstein volume scattering functions
Author(s):Wei, Anhai(1,2); Zhao, Wei(1); Han, Biao(1); Xie, Xiaoping(1,3); Hu, Hui(1); Su, Yulong(1,2)
Source: Guangxue Xuebao/Acta Optica Sinica Volume: 33 Issue: 6 DOI: 10.3788/AOS201333.0601003 Published: June 2013
Abstract:A simulative model with Monte Carlo method is established based on Fournier-Forand and Henyey-Greenstein volume scattering functions, by which propagation characteristics of optical pulse underwater can be analyzed. By using this model, the influence of scattering particles' relative refractive index and size distribution on optical pulse propagation in water is analyzed. The results show that, with the increase of the relative refractive index of scattering particles and small scattering particles' relative quantity, the width of optical pulse is broadened more evidently in time domain, the forward scattering becomes weaker with a more disperse space distribution and arrival angles' distribution. Compared with traditional simulative models, the method presented is more effective.
Accession Number: 20133516679479
-
Record 346 of
Title:Synthesis and photovoltaic properties of an alternating polymer based fluorene and fluorine substituted quinoxaline derivatives
Author(s):Wu, Haimei(1,2); Qu, Bo(3); Tian, Di(1); Cong, Zhiyuan(1); Gao, Bowen(4); Liu, Jianqun(1); An, Zhongwei(1); Gao, Chao(1); Xiao, Lixin(3); Chen, Zhijian(3); Gong, Qihuang(3); Wei, Wei(2)
Source: Reactive and Functional Polymers Volume: 73 Issue: 11 DOI: 10.1016/j.reactfunctpolym.2013.07.015 Published: 2013
Abstract:An alternating polymer (PFOFTQx) with 9,9-dioctylfluorene (FO) as electron-rich unit and fluorine substituted quinoxaline (FTQx) as electron-withdrawing unit was synthesized and characterized. PFOFTQx showed similar absorption property with that of the counterpart polymer without fluorine atom (synthesized APFO-15). However, the low-lying highest occupied molecular orbit (HOMO) energy level of PFOFTQx was -5.37 eV, about 0.07 eV smaller than that of synthesized APFO-15. In order to study the photovoltaic properties of the materials, polymer solar cells (PSCs) were fabricated with PFOFTQx as donor blended with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as acceptor. The power conversion efficiency (PCE) of PSC was 1.77% with a high open-circuit voltage (Voc) of 0.90 V for an optimized PFOFTQx:PC61BM weight ratio of 1:5, in comparison with that of synthesized APFO-15-based device (PCE of 1.60% with Voc of 0.77 V). This study indicated that fluorine substituted quinoxaline-based polymers would be promising material with a higher Voc for the application in polymer solar cells. ? 2013 Elsevier Ltd. All rights reserved.
Accession Number: 20133916791725
-
Record 347 of
Title:Femtosecond multi-beam interference lithography based on dynamic wavefront engineering
Author(s):Zhou, Qiang(1,2); Yang, Wenzheng(1); He, Fengtao(2); Stoian, Razvan(3); Hui, Rongqing(4); Cheng, Guanghua(1,3)
Source: Optics Express Volume: 21 Issue: 8 DOI: 10.1364/OE.21.009851 Published: April 22, 2013
Abstract:A method for precise multi-spot parallel ultrafast laser material structuring is presented based on multi-beam interference generated by dynamic spatial phase engineering. A Spatial Light Modulator (SLM) and digitally programming of phase masks are used to accomplish the function of a multi-facet pyramid lens, so that the laser beam can be spatially modulated to create beam multiplexing and desired two-dimensional (2D) multi-beam interference patterns. Various periodic microstructures on metallic alloy surfaces are fabricated with this technique. A method of preparing extended scale periodic microstructures by loading dynamic time-varying phases is also demonstrated. Scanning electron microscopy (SEM) reveals the period and morphology of the microstructures created using this technique. The asymmetry of interference modes generated from the beams with asymmetric wave vector distributions is equally explored. The flexibility of programming the period of the microstructures is demonstrated. ? 2013 Optical Society of America.
Accession Number: 20131916321286
-
Record 348 of
Title:The application of carbon nanotubes in mode locked fiber laser
Author(s):Yu, Zhenhua(1); Wang, Yonggang(2); Song, Yanrong(1)
Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 8923 Issue: DOI: 10.1117/12.2036094 Published: 2013
Abstract:We demonstrate a mode locked fiber laser based on single wall carbon nanotubes. The mode locking is achieved by the evanescent field interaction of the propagating light with a single wall carbon nanotubes saturable absorber in a microfiber. The pulse width is 114fs. The maximum average output power is 21mW. The center of the wavelength is 1556nm with 26nm spectral width. The repetition rate is 111.6MHz. ? 2013 Copyright SPIE.
Accession Number: 20140817351982
