2014
2014
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Record 325 of
Title:The design of reflective scanning device for drilling the inverted cone micro-hole with femtosecond laser pulses
Author(s):Zhao, Hua-Long(1); Zhou, Ren-Kui(1); Zhao, Wei(1); Yang, Xiao-Jun(1); Li, Ming(1); Jia, Hai-Ni(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 43 Issue: 9 DOI: 10.3788/gzxb20144309.0914006 Published: September 1, 2014Abstract:Based on the Dove Prism scanning principle, a reflective scanning device was designed which was driven by high speed rotating motor and composed of three reflectors in K glyph configuration. The scanning device can be used for the femtosecond laser high-precision spiral drilling system and the accuracy is insensitive to the laser beam quality. The drilling scanning speed is twice as the motor speed with high drilling efficiency. Compared with Dove Prism System, the scanning device is easy to assemble and can avoid the pulse width broadening phenomenon of femtosecond laser. The tests show that it can accomplish high effective drilling the inverted cone micro holes whose diameters are between 0.05 mm and 0.2 mm with the machining accuracy less than ±2 μm.Accession Number: 20144500153454 -
Record 326 of
Title:Tunneling induced dark states and the controllable resonance fluorescence spectrum in quantum dot molecules
Author(s):Tian, Si-Cong(1); Wan, Ren-Gang(2); Tong, Cun-Zhu(1); Ning, Yong-Qiang(1); Qin, Li(1); Liu, Yun(1)Source: Journal of Physics B: Atomic, Molecular and Optical Physics Volume: 47 Issue: 15 DOI: 10.1088/0953-4075/47/15/155503 Published: August 14, 2014Abstract:Optical spectroscopy, a powerful tool for probing and manipulating quantum dots (QDs), has been used to investigate the resonance fluorescence spectrum from linear triple quantum dot molecules controlled by tunneling, using atomic physics methods. Interesting features such as quenching and narrowing of the fluorescence are observed. In such molecules the tunneling between the quantum dots can also induce a dark state. The results are explained by the transition properties of the dressed states generated by the coupling of the laser and the tunneling. Unlike the atomic system, in such quantum dot molecules quantum coherence can be induced using tunneling, requiring no coupling lasers, which will allow tunneling controllable quantum dot molecules to be applied to quantum optics and photonics. ? 2014 IOP Publishing Ltd.Accession Number: 20143218033018 -
Record 327 of
Title:Structure modeling, analysis and thermal experiment of the active cooling focal plane of aspace astronomy telescope
Author(s):Feng, Liang-Jie(1); Ren, Guo-Rui(1); Yang, Wen-Gang(1); Wang, Chen-Jie(1)Source: Yuhang Xuebao/Journal of Astronautics Volume: 35 Issue: 10 DOI: 10.3873/j.issn.1000-1328.2014.10.016 Published: October 30, 2014Abstract:The CCD focal plane of the visible telescope on an astronomy satellite is analysed. The actively cooling structure of the focal plane is designed to satisfy -65℃ working temperature. The maximum stress of the TEC and the thermal conductive adhesive under the working temperature is fully calculated by the finite element method, the results show that the maximum stress of the TEC is 14 MPa and the maximum shear stress of the thermal conductive structure adhesive is 1.2 MPa, which is well below the allowable safety stress. The developed focal plane simulator has passed the thermal vaccum test, and also has validated the cooling ability and the safety of the focal plane assembly.Accession Number: 20144600210424 -
Record 328 of
Title:Optical properties of SrAl2O4: Eu2+ phosphor in glass
Author(s):He, Quanlong(1,2); Hu, Changchuan(3)Source: Optical Materials Volume: 38 Issue: DOI: 10.1016/j.optmat.2014.10.055 Published: December 1, 2014Abstract:Phosphor-in-glass (PiG) typed robust color converters were fabricated using pb-free silicate glasses for luminescence materials applications. The PiG based on a SiO2-B2O3-BaCO3 ternary system and SrAl2O4: Eu2+ phosphor showed good transparency reached 99.50%, even if the GTP ratio is 25:1. By simply changing the mixing ratio of glass to SrAl2O4: Eu2+ phosphor, the emission color of PiG can be controlled from blue to bluish green. The results reveal that the luminescence properties of SrAl2O4: Eu2+ distinct from the phosphor in glass significantly. These suggest that PiG could provide potential application in a variety of luminescence materials. ? 2014 Elsevier B.V. All rights reserved.Accession Number: 20145000317372 -
Record 329 of
Title:Design of magnetic focusing femtosecond streak tube with prepositive traveling wave deflector
Author(s):Wang, Qiangqiang(1,3); Tian, Jinshou(1); Ding, Yongkun(2); Wen, Wenlong(1); Liu, Rong(1,3); Lu, Yu(1); Xu, Xiangyan(1); Cao, Xibin(1); Wang, Xing(1); Wang, Junfeng(1)Source: Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams Volume: 26 Issue: 3 DOI: 10.3788/HPLPB201426.034005 Published: March 2014Abstract:A 265 mm long magnetic focusing femtosecond streak tube with a prepositive traveling wave deflector was theoretically designed. The initial parameters of the electrons emitted both from an ideal point and a slit on the surface of the photoelectric cathode were sampled with Monte Carlo method. The trajectory of the electrons were followed in the CST particle studio, after which the distribution of the electrons on the best image plane and the transit time of the electrons were statistically analyzed. To evaluate the characteristics of the streak tube, this paper also calculated the modulation transform function. The results show that the diameter of the effective area on the photoelectric cathode reaches up to 6 mm, while the amplification rate turns to be 2.4~2.5. By conservative estimates, the time resolution is expected to reach 245 fs.Accession Number: 20141517567156 -
Record 330 of
Title:Control of ultrafast laser nanostructuring of glasses using temporal and spatial pulse design
Author(s):Stoian, R.(1); Mishchik, K.(1); Mauclair, C.(1); Velpula, P.K.(1); Bhuyan, M.K.(1); Colombier, J.P.(1); D'Amico, C.(1); Zamfirescu, M.(2); Cheng, G.(3)Source: Bragg Gratings, Photosensitivity, and Poling in Glass Waveguides, BGPP 2014 Volume: Issue: DOI: 10.1364/bgpp.2014.bw2d.6 Published: July 21, 2014Abstract:Laser transformation of optical glasses depends on the rate of energy feedthrough, affecting the resulting function. We discuss the role of spatio-temporal design of laser pulses in 3D nanostructuring either via self-arrangements or direct writing. ? 2014 OSA.Accession Number: 20145200375909 -
Record 331 of
Title:An Ytterbium-doped fiber laser with dark and Q-switched pulse generation using graphene-oxide as saturable absorber
Author(s):Zhao, Junqing(1); Wang, Yonggang(2); Yan, Peiguang(1); Ruan, Shuangchen(1); Tsang, Yuen(3); Zhang, Gelin(1); Li, Huiquan(1)Source: Optics Communications Volume: 312 Issue: DOI: 10.1016/j.optcom.2013.09.038 Published: 2014Abstract:We demonstrate an ytterbium-doped fiber (YDF) laser being able to generate dark pulses and Q-switched pulses by using a graphene oxide (GO) based composite as saturable absorber (SA). These operation regimes are realized for the first time in a 1-μm band fiber laser as far as our best knowledge. In the fabrication of GO based saturable absorber (GOSA), a vertical evaporation process is included, which results in a GO concentration and thickness variable SA. The generated dark pulse has pulse duration in ns-scale. In the Q-switched operation, pulses with durations from 5.321 μs to 2.655 μs and repetition rates from 28.47 kHz to 58.95 kHz can be obtained as the launched pump power is changed. The transition from the dark pulse to Q-switched operations can be clearly seen as the pump power is increased to a certain value. The radio frequency (RF) and optical spectrum variations with respect to the change of pump power have also been analyzed in detail. ? 2013 Elsevier B.V.Accession Number: 20134316879550 -
Record 332 of
Title:Global method based on Tao stereo matching framework
Author(s):Qi, Min(1); Cao, Jianzhong(1); Zhou, Zuofeng(1); Gao, Bo(1); Guo, Huinan(1); Yang, Lei(1)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 43 Issue: 9 DOI: Published: September 25, 2014Abstract:Traditional stereo matching based on global optimization is of computational complex which is poor to get accuracy matching result for the pixels in occlusion and depth discontinuity region. An efficient method of stereo matching was proposed, which was based on Tao stereo matching framework. Firstly, the initial matching disparity was obtained by the enhanced local method. Then occlusion and mismatched pixels were applied from reliable pixels using the robust method and named unreliable pixels, then reliable pixels and presupposition of disparity plane were used to refine the unreliable disparity. Finally, in order to improve the disparity accuracy in low texture region, an enhanced belief propagation method was used to optimize the refined initial disparity, which had adaptive convergence threshold. Experimental results demonstrate that our method can reduce the error matching rate effectively, improve the matching accuracy in occlusion and depth discontinuity region, reduce the computational complexity as well as improve matching speed.Accession Number: 20144400132259 -
Record 333 of
Title:Control of Ultrafast Laser Nanostructuring of Glasses using Temporal and Spatial Pulse Design
Author(s):Stoian, R.(1); Mishchik, K.(1); Mauclair, C.(1); Velpula, P.K.(1); Bhuyan, M.K.(1); Colombier, J.P.(1); D'Amico, C.(1); Zamfirescu, M.(2); Cheng, G.(3)Source: Optics InfoBase Conference Papers Volume: Issue: DOI: Published: 2014Abstract:Laser transformation of optical glasses depends on the rate of energy feedthrough, affecting the resulting function. We discuss the role of spatio-temporal design of laser pulses in 3D nanostructuring either via self-arrangements or direct writing. ? 2014 OSA.Accession Number: 20223312581644 -
Record 334 of
Title:Spatial and temporal laser pulse design for material processing on ultrafast scales
Author(s):Stoian, R.(1); Colombier, J.P.(1); Mauclair, C.(1); Cheng, G.(1,2); Bhuyan, M.K.(1); Velpula, P.K.(1); Srisungsitthisunti, P.(1,3)Source: Applied Physics A: Materials Science and Processing Volume: 114 Issue: 1 DOI: 10.1007/s00339-013-8081-9 Published: January 2014Abstract:The spatio-temporal design of ultrafast laser excitation can have a determinant influence on the physical and engineering aspects of laser-matter interactions, with the potential of upgrading laser processing effects. Energy relaxation channels can be synergetically stimulated as the energy delivery rate is synchronized with the material response on ps timescales. Experimental and theoretical loops based on the temporal design of laser irradiation and rapid monitoring of irradiation effects are, therefore, able to predict and determine ideal optimal laser pulse forms for specific ablation objectives. We illustrate this with examples on manipulating the thermodynamic relaxation pathways impacting the ablation products and nanostructuring of bulk and surfaces using longer pulse envelopes. Some of the potential control factors will be pointed out. At the same time the spatial character can dramatically influence the development of laser interaction. We discuss spatial beam engineering examples such as parallel and non-diffractive approaches designed for high-throughput, high-accuracy processing events. ? 2013 Springer-Verlag Berlin Heidelberg.Accession Number: 20140817343422 -
Record 335 of
Title:Passively Q-switched Nd:YAG laser with single-walled carbon nanotube in heavy water
Author(s):Wang, Yonggang(1,2); Wang, Yishan(1); Zhang, Xiaojun(2); Wen, Qiao(2)Source: Optics Communications Volume: 321 Issue: DOI: 10.1016/j.optcom.2014.01.067 Published: June 15, 2014Abstract:Carbon nanotubes in heavy water (deuteroxide, D2O) dispersion was fabricated and used as absorber in Q-switched Nd:YVO4 laser for the first time to the best of our knowledge. Such liquid absorber has the virtues of good optical transparency, high heat dissipation and non contact damage. The shortest pulse width of the Q-switched laser is 709 ns, corresponding to 80 kHz repetition rate. The maximum output power of passively Q-switched laser is 214 mW. ? 2014 Elsevier B.V.Accession Number: 20141017416435 -
Record 336 of
Title:Learning to detect stereo saliency
Author(s):Guo, Fang(1); Shen, Jianbing(1); Li, Xuelong(2)Source: Proceedings - IEEE International Conference on Multimedia and Expo Volume: 2014-September Issue: Septmber DOI: 10.1109/ICME.2014.6890321 Published: September 3, 2014Abstract:This paper develops a novel learning-based method for detecting stereo saliency in stereopair images. The disparity maps computed from stereopair images provide an additional depth cue for stereo saliency detection. To the best of our knowledge, our approach is the first one to simultaneously detect the stereo saliency of both left and right images using support vector machine (SVM). In our work, the disparity maps are used in two aspects. One is to improve the performance of saliency detection for monocular image. The other one is to maintain the consistency between the stereo matching and saliency maps. In order to meet the above requirements, we propose a new combinational saliency feature to train the stereo images with the labeled saliency ground truth, using support vector machine as the classifier. In the test stage, our approach generates the stereo saliency results according to the trained SVM model. Furthermore, a stereopair saliency dataset containing 400 pairs of images is created to perform the challenging experiments. The experimental results have demonstrated that our method achieves better performance than the state-of-the-art algorithms of single-image saliency detection. ? 2014 IEEE.Accession Number: 20153001066505