2016
2016
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Record 157 of
Title:Block Principal Component Analysis with Nongreedy 1 -Norm Maximization
Author(s):Li, Bing Nan(1); Yu, Qiang(2); Wang, Rong(2); Xiang, Kui(3); Wang, Meng(4); Li, Xuelong(5)Source: IEEE Transactions on Cybernetics Volume: 46 Issue: 11 DOI: 10.1109/TCYB.2015.2479645 Published: November 2016Abstract:Block principal component analysis with 1-norm (BPCA-L1) has demonstrated its effectiveness in a lot of visual classification and data mining tasks. However, the greedy strategy for solving the 1-norm maximization problem is prone to being struck in local solutions. In this paper, we propose a BPCA with nongreedy 1-norm maximization, which obtains better solutions than BPCA-L1 with all the projection directions optimized simultaneously. Other than BPCA-L1, the new algorithm has been evaluated against some popular principal component analysis (PCA) algorithms including PCA-L1 and 2-D PCA-L1 on a variety of benchmark data sets. The results demonstrate the effectiveness of the proposed method. ? 2013 IEEE.Accession Number: 20173404066437 -
Record 158 of
Title:Dynamic characteristic analysis on streak image tube with high temporal resolution
Author(s):Liu, Rong(1,2); Tian, Jin-Shou(2); Miao, Run-Cai(1); Wang, Qiang-Qiang(2); Wen, Wen-Long(2); Li, Yan(3); Wang, Jun-Feng(2); Xu, Xiang-Yan(2); Lu, Yu(2); Liu, Hu-Lin(2); Wang, Xing(2)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 45 Issue: 10 DOI: 10.3788/gzxb20164510.1012001 Published: October 1, 2016Abstract:Aim to high temporal resolution of the streak image tube in streak camera, the factors which influence the physical temporal dispersion, technical temporal dispersion and time jitter of the sweep circuit were discussed. The streak image tube was optimized, in which a pair of traveling wave deflectors was located before a magnetic solenoid lens. The inner time-varying electric field of traveling wave deflectors was simulated by CST electromagnetic studio. And the propagation velocity of electromagnetic wave was calculated. The results show that when leg length is 8 mm, leg width is 1mm, interval is 0.24 mm, pin length is 2.5 mm, deflector thickness is 1 mm and deflector length is 17.12 mm, the moving velocity of electrons and propagation velocity of the electromagnetic wave are matching. Based on the electron trajectory tracing method and the Rayleigh criterion, dynamic temporal and spatial characteristics of the streak image tube were analyzed, a dynamic temporal resolution of 200 fs in single sweep mode, dynamic temporal resolution of 208 fs in synchronized sweep mode, and a dynamic spatial resolution of above 20 lp/mm were obtained. ? 2016, Science Press. All right reserved.Accession Number: 20164302952417 -
Record 159 of
Title:Reduction of phase noise to amplitude noise conversion in silicon waveguide-based phase-sensitive amplification
Author(s):Ma, Yonghua(1); Liu, Hongjun(1); Sun, Qibing(1); Huang, Nan(1); Wang, Zhaolu(1)Source: Applied Optics Volume: 55 Issue: 12 DOI: 10.1364/AO.55.003140 Published: April 20, 2016Abstract:We use a vector phase sensitive amplification (PSA) scheme, which can eliminate the inherent phase noise (PN) to amplitude noise (AN) conversion in a conventional PSA process. A dispersion-engineered silicon strip waveguide is used to investigate the vector PSA scheme at the telecom wavelengths. The phase-dependent gain and phase-tophase transfer functions as well as constellation diagram at different signal polarization states (SPSs) are numerically analyzed. It is found that the PN to AN conversion is completely suppressed when the SPS is identical to one of the pump polarization states. Moreover, the binary phase shift keying signal is regenerated by the proposed vector PSA scheme, and the error vector magnitude is calculated to assess the regeneration capacity. Our results have potential application in all-optical signal processing. ? 2016 Optical Society of America.Accession Number: 20161802333755 -
Record 160 of
Title:Thermal tunability of photonic bandgaps in liquid crystal filled polymer photonic crystal fiber
Author(s):Wang, Doudou(1); Chen, Guoxiang(2); Wang, Lili(3)Source: Optical Fiber Technology Volume: 29 Issue: DOI: 10.1016/j.yofte.2016.04.004 Published: May 2016Abstract:A highly tunable bandgap-guiding polymer photonic crystal fiber is designed by infiltrating the cladding air holes with liquid crystal 5CB. Structural parameter dependence and thermal tunability of the photonic bandgaps, mode properties and confinement losses of the designed fiber are investigated. Bandgaps red shift as the temperature goes up. Average thermal tuning sensitivity of 30.9 nm/°C and 20.6 nm/°C is achieved around room temperature for the first and second photonic bandgap, respectively. Our results provide theoretical references for applications of polymer photonic crystal fiber in sensing and tunable fiber-optic devices. ? 2016 Elsevier Inc. All rights reserved.Accession Number: 20161702282107 -
Record 161 of
Title:High peak power mid-infrared 2.8 μm pulsed fiber laser
Author(s):Shen, Yan-Long(1,2); Wang, Yi-Shan(2,3); Chen, Hong-Wei(1); Huang, Ke(1); Tao, Meng-Meng(1); Luan, Kun-Peng(1); Yu, Li(1); Yi, Ai-Ping(1); Feng, Guo-Bin(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 45 Issue: 11 DOI: 10.3788/gzxb20164511.1114002 Published: November 1, 2016Abstract:A high peak power actively Q-switched mid-infrared fiber laser at 2.8 μm was demonstrated with a repetition rate of 1~10 kHz by employing a 975 nm laser-diode to pump a piece of heavily Er3+-doped ZBLAN double-clad fiber and a mechanical chopper into the cavity as the Q-switch. Stable Q-switched laser pulse with a maximum pulse energy of 134.5 μJ, pulse duration of 127.3 ns and peak power of 1.1 kW was obtained at a repetition rate of 10 kHz under a proper pump power. ? 2016, Science Press. All right reserved.Accession Number: 20164703047436 -
Record 162 of
Title:Extracting signal via stochastic resonance in the semiconductor optical amplifier
Author(s):Zhao, Wulong(1); Liu, Hongjun(1); Sun, Qibing(1); Huang, Nan(1); Wang, Zhaolu(1); Han, Jing(1); Sun, Heng(1)Source: Chinese Optics Letters Volume: 14 Issue: 8 DOI: 10.3788/COL201614.081901 Published: August 10, 2016Abstract:The stochastic resonance based on optical bistability in the semiconductor optical amplifier is numerically investigated to extract a weak pulse signal buried in noise. The output property of optical bistability under different system parameters is analyzed, which determines the performance of the stochastic resonance. Through optimizing these parameters, the noise-hidden signal is extracted via stochastic resonance, in which the maximum cross-correlation gain higher than nine is obtained. This provides a novel technology for detecting a weak optical signal in various signal processing fields. ? 2016 Chinese Optics Letters.Accession Number: 20163702806376 -
Record 163 of
Title:Pulse duration tunable fiber CPA system based on thermally dispersion tuning of chirped fiber bragg grating
Author(s):Zhang, Xin(1); Yang, Zhi(1); Li, Qianglong(1); Li, Feng(1); Yang, Xiaojun(1); Wang, Yishan(1); Zhao, Wei(1)Source: Optik Volume: 127 Issue: 20 DOI: 10.1016/j.ijleo.2016.06.062 Published: October 1, 2016Abstract:A pulse width tunable fiber-based chirp pulse amplification (CPA) system had been built by our newly developed dispersion tuning mechanism. In order to realize dispersion fine tuning, we changed the temperature of chirped fiber Bragg grating (CFBG), which was used as stretcher in CPA system, to change the dispersion compensation level between stretcher and grating pairs compressor. By the help of this method, the minimum pulse width after compression can be obtained by balancing the dispersion of the stretcher and of the compressor. In our experimental fiber CPA system, the minimum pulse duration of 780?fs was recorded by autocorrelator during the CFBG temperature tuning at temperature range of 0?°C to 50?°C, and the pulse tuning accuracy can reach about 3?fs/?°C. ? 2016 Elsevier GmbHAccession Number: 20162802581608 -
Record 164 of
Title:Passively Q-switched nd:YAG laser via a WS2 saturable absorber
Author(s):Wang, Xi(1); Wang, Yonggang(1); Duan, Lina(1); Li, Lu(1); Sun, Hang(1)Source: Optics Communications Volume: 367 Issue: DOI: 10.1016/j.optcom.2016.01.066 Published: May 15, 2016Abstract:In this work, we report a passively Q-switched Nd:YAG laser at 1064 nm by using WS2 solution as the saturable absorber (SA). The WS2 solution with different concentrations (0.25, 0.5, and 1 mg/ml) were fabricated by the liquid-phase-exfoliated method and injected into quartz cells. Such liquid absorbers have the virtues of adjustable optical absorption, high heat dissipation and non-contact damage. By inserting those WS2 solutions in the laser cavity, stable Q-switched laser operations were obtained. The corresponding pulse duration as short as 922 ns was obtained. The result shows that the WS2 material can be act as absorber for solid-state lasers. ? 2016 Elsevier B.V. All rights reserved.Accession Number: 20161202118757 -
Record 165 of
Title:WS2/fluorine mica (FM) saturable absorber for high power optical pulse formation
Author(s):Li, L.(1,2); Wang, Z.F.(2); Wang, Y.G.(2); Wang, X.(2); Yang, G.W.(2)Source: Optik Volume: 127 Issue: 21 DOI: 10.1016/j.ijleo.2016.08.040 Published: November 1, 2016Abstract:The report presents the high power mode-locking operation in an anomalous-dispersion fiber laser with a novel WS2 saturable absorber (SA) based on fluorine mica (FM) substrate. Compared to organic host material such as polymer, FM has higher softening temperature, heat dissipation and laser damage threshold. By employing the SA, a stable mode-locked fiber laser is achieved. The duration of the pulse broadens from 2.816 ns to 3.654 ns almost linearly with increasing pump power. The average output power and single pulse energy can increase up to 33.5 mW and 4 nJ at the maximum pump power respectively. The results indicate that WS2/FM material is an ideal SA for high power Er-doped fiber (EDF) lasers. ? 2016 Elsevier GmbHAccession Number: 20163502755972 -
Record 166 of
Title:Influence of temperature on "Smile" in high power diode laser bars
Author(s):Wang, Shu-Na(1); Zhang, Pu(1); Xiong, Ling-Ling(1); Nie, Zhi-Qiang(1); Wu, Di-Hai(1); Liu, Xing-Sheng(1,2)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 45 Issue: 5 DOI: 10.3788/gzxb20164505.0514001 Published: May 1, 2016Abstract:By the numerical modeling and experimental test, the influence of temperature on "smile" was studied. By using the finite element method, the thermal stresses induced during bar bonding and operating process were simulated respectively. In simulations, it is assumed that the deformation of the laser bar is only caused by the thermal stress. The simulated results show that the thermal stress across the laser bar decreases with the increasing of heatsink temperature. As thus, the curve of the laser bar induced by packaging thermal stress will decrease with the increasing of the temperature. In this experiment, "smile" of five samples from the same wafer and batch was measured under different heatsink temperatures. Experimental results show that "smile" of the five samples increases or decreases as heatsink temperature increasing. The possible reason which is related with the combined action between the primitive bending shape of the bare bar and the mounting thermal stress. If the bare bar before packaging is flat or convex, "smile" of the diode laser bar will decrease as the heatsink temperature increasing. In addition, if the bare bar is concave and the laser bar is still concave after packaging, "smile" will increase with the increasing of heatsink temperature. ? 2016, Science Press. All right reserved.Accession Number: 20162402489937 -
Record 167 of
Title:Investigation on high-efficient terahertz source based on two-color femtosecond laser-induced air plasma
Author(s):Fan, Wen-Hui(1); Chen, Ze-You(1); Xie, Jun(1); Chen, Xu(1); Tang, Jie(1); Zhao, Wei(1)Source: Optics InfoBase Conference Papers Volume: Issue: DOI: 10.1364/ISUPTW.2016.IW3A.2 Published: 2016Abstract:Terahertz radiation generated by two-color laser-induced air plasma has been investigated systematically. A highly efficient terahertz source has been achieved and can be utilized to carry out further investigation on terahertz sensing, spectroscopy, and imaging. ? OSA 2016.Accession Number: 20171403544447 -
Record 168 of
Title:Spatiotemporal soliton solution to generalized nonlinear Schr?dinger equation with a parabolic potential in Kerr media
Author(s):Kong, Youchao(1)Source: Optics Communications Volume: 371 Issue: DOI: 10.1016/j.optcom.2016.03.004 Published: July 15, 2016Abstract:A class of new spatiotemporal solitary solution to nonlinear Schr?dinger equation with a parabolic potential is investigated analytically and numerically using the F-expansion method and homogeneous balance principle. The propagation characteristics of soliton wave solutions are analyzed with/without spatial-temporal chirp. It is noteworthy that, by calculating spatial and temporal second-order intensity moment, several novel features of optical beam propagations are obtained, such as stable, oscillating, decaying and blowing up. Additionally, controllability of these solutions with the modulation depth of the parabolic potential is demonstrated. ? 2016 Elsevier B.V.Accession Number: 20161402186212