2017
2017
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Record 277 of
Title:A Method for Solving the Refractive Index Temperature Coefficient Empirical Formula Constants of Optical Glasses Based on 1st Opt
Author(s):Ma, Zhi-Yuan(1); Wang, Peng-Fei(2); Wu, Zhi-Qiang(1); Wu, De-Lin(1); Su, Yong(1)Source: Guangzi Xuebao/Acta Photonica Sinica Volume: 46 Issue: 6 DOI: 10.3788/gzxb20174606.0616002 Published: June 1, 2017Abstract:In order to solve the problem that large deviation of the refraction index and temperature coefficient of refraction index obtained by regression calculation from the experimentally measured ones comes out when ZEMAX method is used for solving these empirical formula constants and regression calculation, 1stOpt differential evolution was used to calculate the temperature coefficient of refraction index empirical formula constants. With fluoro-crown D-FK61 and flint H-TF3A optical glass as examples, the λtk coefficients calculated by the proposed method are consistent with the general numerical range of 0.08~0.33, and the difference of refractive index and its temperature coefficient between the value obtained by regression calculation method and the measured value is less than 1×10-5 and 2×10-7/℃, respectively. As an effective supplement of ZEMAX software to calculate the temperature coefficient of refractive index of the optical glasses, the proposed method greatly improves the accuracy and can provide accurate optical parameter guarantee for thermal compensation optical system design. ? 2017, Science Press. All right reserved.Accession Number: 20173104014349 -
Record 278 of
Title:Complete indium-free CW 200W passively cooled high power diode laser array using double-side cooling technology
Author(s):Wang, Jingwei(1); Zhu, Pengfei(1); Liu, Hui(2); Liang, Xuejie(1); Wu, Dihai(2); Liu, Yalong(1); Yu, Dongshan(1); Zah, Chung-En(1); Liu, Xingsheng(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10085 Issue: DOI: 10.1117/12.2253442 Published: 2017Abstract:High power diode lasers have been widely used in many fields. To meet the requirements of high power and high reliability, passively cooled single bar CS-packaged diode lasers must be robust to withstand thermal fatigue and operate long lifetime. In this work, a novel complete indium-free double-side cooling technology has been applied to package passively cooled high power diode lasers. Thermal behavior of hard solder CS-package diode lasers with different packaging structures was simulated and analyzed. Based on these results, the device structure and packaging process of double-side cooled CS-packaged diode lasers were optimized. A series of CW 200W 940nm high power diode lasers were developed and fabricated using hard solder bonding technology. The performance of the CW 200W 940nm high power diode lasers, such as output power, spectrum, thermal resistance, near field, far field, smile, lifetime, etc., is characterized and analyzed. ? 2017 SPIE.Accession Number: 20172103685882 -
Record 279 of
Title:Balanced clustering with least square regression
Author(s):Liu, Hanyang(1); Han, Junwei(1); Nie, Feiping(2); Li, Xuelong(3)Source: 31st AAAI Conference on Artificial Intelligence, AAAI 2017 Volume: Issue: DOI: Published: 2017Abstract:Clustering is a fundamental research topic in data mining. A balanced clustering result is often required in a variety of applications. Many existing clustering algorithms have good clustering performances, yet fail in producing balanced clusters. In this paper, we propose a novel and simple method for clustering, referred to as the Balanced Clustering with Least Square regression (BCLS), to minimize the least square linear regression, with a balance constraint to regularize the clustering model. In BCLS, the linear regression is applied to estimate the class-specific hyperplanes that partition each class of data from others, thus guiding the clustering of the data points into different clusters. A balance constraint is utilized to regularize the clustering, by minimizing which can help produce balanced clusters. In addition, we apply the method of augmented Lagrange multipliers (ALM) to help optimize the objective model. The experiments on seven real-world benchmarks demonstrate that our approach not only produces good clustering performance but also guarantees a balanced clustering result. Copyright ? 2017, Association for the Advancement of Artificial Intelligence (www.aaai.org). All rights reserved.Accession Number: 20174104243167 -
Record 280 of
Title:Ultra-short wavelength operation in Thulium-doped silica fiber laser with bidirectional pumping
Author(s):Xiao, Xusheng(1,2); Guo, Haitao(1); Yan, Zhijun(1); Wang, Hushan(1); Xu, Yantao(1); Lu, Min(1); Wang, Yishan(1); Peng, Bo(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10256 Issue: DOI: 10.1117/12.2256818 Published: 2017Abstract:An ultra-short wavelength operation of Tm-doped all fiber laser based on fiber Bragg gratings (FBGs) was developed. A bi-directional pump configuration for the ultra-short wavelength operation was designed and investigated for the first time. the laser yielded 3.15W of continuous-wave output at 1706.75nm with a narrow-linewidth of ～50pm and a maximum slope efficiency of 42.1%. The dependencies of the slope efficiencies and pump threshold of the laser versus the length of active fiber and reflectivity of the output mirror (FBG) were investigated in detail. An experimental comparative study between two Thulium-doped fiber lasers (TDFLs) with two different pumping configuration(forward unidirectional pumping and bidirectional pumping) was presented. It is indisputable that the development of 1.7μm silicate fiber lasers with Watt-level output power open up a number of heart-stirring and tempting application windows. ? 2017 SPIE.Accession Number: 20171703607634 -
Record 281 of
Title:Photonic microwave and mm-wave mixer for multichannel fiber transmission
Author(s):Gao, Yongsheng(1,2); Wen, Aijun(2,3); Zhang, Wu(2,3); Wang, Yong(2,3); Zhang, Huixing(2,4)Source: Journal of Lightwave Technology Volume: 35 Issue: 9 DOI: 10.1109/JLT.2017.2652122 Published: May 1, 2017Abstract:Photonic microwave and millimeter wave (mm-wave) frequency conversion is a promising technique for future electronic systems due to its large bandwidth, electromagnetic immunity, and compatibility with other optical systems. However, the conversion gain of a photonic mixer is often low and may be further reduced by the fiber dispersion. In this paper, a photonic microwave and mm-wave mixer using an integrated polarization division multiplexing Mach-Zehnder modulator (PDM-MZM) is proposed, which exhibits the merits of high conversion gain, high purity, and compensation of the power fading in multichannel fiber transmission. By suppressing the optical carrier and optimizing the modulation index, the conversion gain and isolation are respectively improved by 27.6 and 55.3 dB in the experiment. After power compensation, high and relatively flat microwave and mm-wave signals from 12 to 45 GHz are obtained after transmission over 25-km fiber. In addition, an up-converted 38-GHz mm-wave signal carrying 100-MSym/s 16-quadrature amplitude modulation (16QAM) vector signal is simultaneously transmitted over four channels with different fiber length (back to back, 4, 25, and 50 km). The power fading in each channel can be independently compensated, and good electrical spectra, constellation diagrams, and receiver sensitivity are obtained. ? 2017 IEEE.Accession Number: 20171803618683 -
Record 282 of
Title:Interleaved segment correction achieves higher improvement factors in using genetic algorithm to optimize light focusing through scattering media
Author(s):Li, Runze(1,2,3); Peng, Tong(1,3); Liang, Yansheng(1,3); Yang, Yanlong(1); Yao, Baoli(1); Yu, Xianghua(1); Min, Junwei(1); Lei, Ming(1); Yan, Shaohui(1); Zhang, Chunmin(2); Ye, Tong(4)Source: Journal of Optics (United Kingdom) Volume: 19 Issue: 10 DOI: 10.1088/2040-8986/aa84dc Published: September 13, 2017Abstract:Focusing and imaging through scattering media has been proved possible with high resolution wavefront shaping. A completely scrambled scattering field can be corrected by applying a correction phase mask on a phase only spatial light modulator (SLM) and thereby the focusing quality can be improved. The correction phase is often found by global searching algorithms, among which Genetic Algorithm (GA) stands out for its parallel optimization process and high performance in noisy environment. However, the convergence of GA slows down gradually with the progression of optimization, causing the improvement factor of optimization to reach a plateau eventually. In this report, we propose an interleaved segment correction (ISC) method that can significantly boost the improvement factor with the same number of iterations comparing with the conventional all segment correction method. In the ISC method, all the phase segments are divided into a number of interleaved groups; GA optimization procedures are performed individually and sequentially among each group of segments. The final correction phase mask is formed by applying correction phases of all interleaved groups together on the SLM. The ISC method has been proved significantly useful in practice because of its ability to achieve better improvement factors when noise is present in the system. We have also demonstrated that the imaging quality is improved as better correction phases are found and applied on the SLM. Additionally, the ISC method lowers the demand of dynamic ranges of detection devices. The proposed method holds potential in applications, such as high-resolution imaging in deep tissue. ? 2017 IOP Publishing Ltd.Accession Number: 20174204273453 -
Record 283 of
Title:The study of quantum spectral imaging
Author(s):Bi, Siwen(1,2); Wang, Guoguo(2); Wang, Li(2); Chen, Mingrui(2); Dou, Xibo(2); Liu, Wangyun(2); Chen, Lu(2); Lu, Baozhu(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 10111 Issue: DOI: 10.1117/12.2250112 Published: 2017Abstract:At the beginning of 2001, Professor Siwen Bi first proposed the new direction of quantum remote sensing at home and abroad. Based on the research of fundamental theory and information mechanism of quantum remote sensing, a new concept of quantum spectral imaging was put forward in August 2006. 10 years, quantum spectral imaging research has made breakthrough progress and stage results. Firstly, the research status of spectral imaging and the background of quantum spectrum imaging are introduced. Secondly, the concept and research methods of quantum spectrum imaging, the relationship between quantum spectrum imaging and spectral imaging and advantages are introduced. The basic theory of quantum spectroscopy is described, especially the research of quantum spectroscopy imaging and quantum spectroscopy. Finally, the significance and application prospect of quantum spectrum imaging are described. ? 2017 SPIE.Accession Number: 20175304592810 -
Record 284 of
Title:Er-doped mode-locked fiber laser with WS2/fluorine mica (FM) saturable absorber
Author(s):Li, Lu(1,4); Wang, Yonggang(1,2); Wang, Xi(1); Yang, Guowen(1); Jiang, Shouzhen(3); Li, Zhen(3); Man, Baoyuan(3); Wang, Yishan(1)Source: Optics and Laser Technology Volume: 90 Issue: DOI: 10.1016/j.optlastec.2016.10.011 Published: May 1, 2017Abstract:The report presents conventional soliton 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 composite, FM has higher softening temperature, heat dissipation and laser damage threshold. In this work, the modulation depth (MD) and non-saturable loss (NL) of WS2/FM SA are measured to be 3.1% and 15%, respectively. By employing the SA, a stable conventional soliton mode-locked fiber laser is achieved. The repetition rate is 8.2 MHz and the pulse duration is 830 fs. The fiber laser works in mode locking operation for at least ten days and no damage of the SA is observed. The results indicate that WS2/FM material is an ideal SA for Er-doped fiber (EDF) lasers. ? 2016 Elsevier LtdAccession Number: 20164703044365 -
Record 285 of
Title:Automatic Lumen Segmentation in Intravascular Optical Coherence Tomography Images Using Level Set
Author(s):Cao, Yihui(1,2,3); Cheng, Kang(4); Qin, Xianjing(5,6); Yin, Qinye(2); Li, Jianan(1); Zhu, Rui(1); Zhao, Wei(1)Source: Computational and Mathematical Methods in Medicine Volume: 2017 Issue: DOI: 10.1155/2017/4710305 Published: 2017Abstract:Automatic lumen segmentation from intravascular optical coherence tomography (IVOCT) images is an important and fundamental work for diagnosis and treatment of coronary artery disease. However, it is a very challenging task due to irregular lumen caused by unstable plaque and bifurcation vessel, guide wire shadow, and blood artifacts. To address these problems, this paper presents a novel automatic level set based segmentation algorithm which is very competent for irregular lumen challenge. Before applying the level set model, a narrow image smooth filter is proposed to reduce the effect of artifacts and prevent the leakage of level set meanwhile. Moreover, a divide-and-conquer strategy is proposed to deal with the guide wire shadow. With our proposed method, the influence of irregular lumen, guide wire shadow, and blood artifacts can be appreciably reduced. Finally, the experimental results showed that the proposed method is robust and accurate by evaluating 880 images from 5 different patients and the average DSC value was 98.1%±1.1%. ? 2017 Yihui Cao et al.Accession Number: 20214511123267 -
Record 286 of
Title:Several nanosecond Nd:YVO4 lasers Q-switched by two dimensional materials: Tungsten disulfide, molybdenum disulfide, and black phosphorous
Author(s):Liu, Huan(1,2); Sun, Zhe(1); Wang, Xi(1,2); Wang, Yonggang(3); Cheng, Guanghua(1)Source: Optics Express Volume: 25 Issue: 6 DOI: 10.1364/OE.25.006244 Published: March 20, 2017Abstract:Graphene-like two-dimensional (2D) materials have shown remarkable broadband saturable absorption properties. These materials were successfully applied into mode locked lasers to generate laser pulses with the pulse duration from picosecond to femtosecond. However, these novel materials have not shown good performance as far in another important aspect: Q-switched lasers. Solid-state or fiber lasers Q-switched with broadband absorbers usually generated pulses of one hundred nanosecond to several microsecond, which show weak competitiveness compared to traditional absorbers such as Cr: YAG and semiconductor saturable absorption mirror (SESAM). In this paper we utilized BP, WS2 and MoS2 solutions as saturable absorbers (SAs) to construct the passively Q-switched Nd:YVO4 lasers. The pulse durations as short as 2.86 nanosecond was obtained. To the best of our knowledge, it was the first report that the pulse durations approached several nanosecond level in Q-switched lasers with liquid-form of BP, WS2 and MoS2 SAs. ? 2017 Optical Society of America.Accession Number: 20171203489550 -
Record 287 of
Title:Thermal characteristics of kW-level conduction-cooled semiconductor laser array
Author(s):Zhu, Qiwen(1,2); Zhang, Pu(1); Wu, Dihai(1); Nie, Zhiqiang(1); Xiong, Lingling(1); Liu, Xingsheng(1,3)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 46 Issue: 10 DOI: 10.3788/IRLA201746.1005003 Published: October 25, 2017Abstract:With the increase in output power of high power semiconductor lasers(HPSLs), thermal management is one of the critical bottlenecks affecting the optical-electrical performance and reliability of HPSLs. Thermal characteristics of a kW-level conduction cooled semiconductor laser array were analyzed based on numerical simulations and experiments. Firstly, transient thermal behavior was studied using finite element method (FEM). There is significant "thermal crosstalk" behavior among the semiconductor laser bars with pulse width greater than 250 μs. It shows thermal resistances along horizontal and vertical directions are 64.7% and 35.3%, respectively, indicating that heat mainly dissipates along horizontal direction. 74.9% of thermal resistance along horizontal direction and 66.5% of thermal resistance along vertical direction origin from CuW layer, which shows that CuW is the most significant factor affecting the efficiency of thermal dissipation. Based on accumulated average temperature method, the simulated temperature differences are 2.13, 1.47, 0.75℃ at the repetition frequencies of 20, 30 and 40 Hz compared with that at the frequency of 50 Hz. Average junction temperature rises at different repetition frequency have been measured using spectral method, and the temperature differences at the repetition frequencies of 20, 30 and 40 Hz are 2.33, 1.56, 0.78℃, respectively. The average error is less than 6.85% between experiment results and numerical simulation. It shows that the simulated transient thermal resistance is coincident with the experimental result. ? 2017, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.Accession Number: 20175004542616 -
Record 288 of
Title:Visible and near-infrared optical properties of Nd:CLNGG crystal waveguides formed by proton implantation
Author(s):Liu, Chun-Xiao(1); Shen, Xiao-Liang(1); Li, Wei-Nan(2); Wei, Wei(1)Source: Chinese Physics B Volume: 26 Issue: 3 DOI: 10.1088/1674-1056/26/3/034207 Published: March 2017Abstract:A Nd:CLNGG waveguide structure operated at wavelengths of both 632.8 nm and 1539 nm was demonstrated for the first time to our knowledge, which was produced by the 480-keV H+ ion implantation with a dose of 1.0 × 1017 protons/cm2. Its propagating modes at 632.8 nm and 1539 nm were measured by the well-known prism coupling technique. The refractive index profile at either 632.8-nm wavelength or 1539-nm wavelength was optical barrier type in the proton-implanted Nd:CLNGG crystal optical waveguide, which was calculated by using the reflectivity calculation method. The near-field light intensity distributions were also simulated by the finite-difference beam propagation method in the visible and nearinfrared bands. ? 2017 Chinese Physical Society and IOP Publishing Ltd.Accession Number: 20171203485833