2019
2019
-
Record 445 of
Title:Thermally Accelerated Aging Test of Conduction-cooled-packaged High Power Diode Laser Bar in CW Mode
Author(s):Nie, Zhi-Qiang(1); Wang, Ming-Pei(2); Sun, Yu-Bo(2); Li, Xiao-Ning(3); Wu, Di(3)Source: Faguang Xuebao/Chinese Journal of Luminescence Volume: 40 Issue: 9 DOI: 10.3788/fgxb20194009.1136 Published: September 1, 2019Abstract:In the applications of high power semiconductor laser(HLD), the reliability is the important performance. Therefore lifetime evaluation and reliability analysis technologies become the key of practical application and industrialization of HLD. The thermally accelerated aging test is able to monitor the failure process, reveal defects and weak links of device design process, materials and components, and provides guidance for optimizing the chip and package structure. It is an important technology of lifetime evaluation and reliability analysis. In this work, a thermally accelerated aging test of eighteen conduction-cooled-packaged 60 W 808 nm high power diode laser arrays packaged by indium solder in CW mode at constant current 60 A under the temperature 55, 65, 80℃ of heat sink has been reported. According to the decreasing trend of the output power during the thermal acceleated aging test, the lifetime 1 022, 620, 298 h have been obtained, respectively. Based on the Arrhenius formula, the activation energy of the device is 0.565 41 eV, and the lifetime of the device is 5 762 h at room temperature. It can be seen that the lifetime of the device accelerates by 5 times at 55℃, 8.5 times at 65℃ and 17 times at 80℃. In addition, we show and analyze the performance of the device after accelerated aging test. ? 2019, Science Press. All right reserved.Accession Number: 20194107528634 -
Record 446 of
Title:Silicon drift detector applied to X-ray pulsar navigation
Author(s):Xu, Neng(1,2,3); Sheng, Lizhi(1); Su, Tong(1,3); Chen, Chen(1,3); Li, Yao(1,3); Zhao, Baosheng(1); Liu, Chunliang(2)Source: Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment Volume: 927 Issue: DOI: 10.1016/j.nima.2019.03.007 Published: 21 May 2019Abstract:In this paper, a focused detection system for X-ray pulsar-based Navigation (XNAV) is designed based on Silicon Drift Detector (SDD). The detector electronics mainly adopts the digital trapezoidal shaping method to measure the Times-Of-Arrival (TOAs) and energy of photons. The time measurement accuracy is better than 500ns. The energy resolution is 191eV at 8.05keV, and the maximum count rate is 500kcps between 1 and 12keV. In the semi-physical simulation experiment, the filtering of noise photons by energy discrimination significantly improves the correlation degree between the cumulative pulse profile and the standard profile. ? 2019Accession Number: 20191106617663 -
Record 447 of
Title:Toroidal metasurfaces integrated with microfluidic for terahertz refractive index sensing
Author(s):Chen, Xu(1); Fan, Wenhui(1,2,3)Source: Journal of Physics D: Applied Physics Volume: 52 Issue: 48 DOI: 10.1088/1361-6463/ab3ea0 Published: September 12, 2019Abstract:A terahertz refractive index sensor consisting of toroidal dipole resonance metasurface integrated with microfluidic channel is proposed. The excitation of toroidal dipole resonance in this metasurface and the localized electromagnetic field enhancement in microfluidic channel are investigated comprehensively. Numerical results show that the calculated quality factor and the corresponding figure of merit can reach 1103 and 244, much higher than previously reported terahertz metamaterials sensors. Moreover, the refractive index sensing capabilities of non-polar and polar liquids are also investigated, which demonstrate the resonant frequency shift does not depend on the losses of analytes and show this device can be used for sensing various materials, including highly absorptive materials. This proposed structure can be extended to work in other frequency regions and has potential applications in high performance gases, liquids and biological materials sensing. ? 2019 IOP Publishing Ltd.Accession Number: 20194207534627 -
Record 448 of
Title:MCP gain and its influence on ultraviolet photon counting imaging detectors
Author(s):Liu, Yong-An(1,2,3); Xu, Neng(2,3); Shi, Feng(2); Liu, Zhe(2); Sai, Xiao-Feng(2); Sheng, Li-Zhi(2); Tian, Jin-Shou(2); Zhao, Bao-Sheng(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11023 Issue: DOI: 10.1117/12.2521274 Published: 2019Abstract:Micro-channel Plates(MCPs) are an important part of ultraviolet photon counting imaging detectors. They can intensify single particles or photons by the multiplication of electrons via secondary emission.Thus, the MCP gain has an very important influence on the performance of ultraviolet photon counting imaging detectors. In this article, influence of MCP gain on decoding accuracy is studied by using Monte Carlo method. Simulation results show that decoding error is large when MCP gain is low,and MCPs shoud have at least 106 gain to ensure accurate decoding. At the same time, influence of MCP gain on decoding error was tested by using ultraviolet photon counting imaging system based on TWA(Tetra Wedge Anode,TWA). Experimental results are consistent with the theoretical analysis and simulation. ? 2019 SPIE.Accession Number: 20191506748615 -
Record 449 of
Title:Research on precision space linear rolling guide dynamics
Author(s):Cheng, Penghui(1,2); Wu, Mengyuan(1); Li, Chuang(1); Ma, Xiaozhe(1,2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11063 Issue: DOI: 10.1117/12.2539145 Published: 2019Abstract:Linear rolling guide have widely used in precision machinery today, with significant advantages such as high precision, low traction and low wear. Research on the dynamic characteristics of precision linear rolling guide became very important for space applications due to the continuous improvement of the manufacturing level of high-precision equipment. The THK's RSR small precision guide is studied in this research. The model of guide joint is established by optimized tandem damping element with the finite element method to simulate the dynamic stiffness and ball mass of the guide joint. The analytical formula based on Hertzian contact theory is adopted in this research to obtain the dynamic parameters of the guide joint. Accomplishing the the dynamic simulation analysis of the precision guide based on the finite element method by MSC.Patran & Nastran software. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.Accession Number: 20195207919107 -
Record 450 of
Title:Temporal analysis of Airy beam propagation in photorefractive media
Author(s):Zhang, M.Z.(1); Zhang, T.Y.(2); Huo, G.W.(3); Hui, Z.Q.(1); Duan, Z.L.(1); Zha, X.W.(1)Source: Communications in Nonlinear Science and Numerical Simulation Volume: 76 Issue: DOI: 10.1016/j.cnsns.2019.04.011 Published: September 2019Abstract:We theoretically examine the temporal behavior of Airy beams and their interactions in photorefractive medium with the split-step Fourier method. Simulations indicate that Airy beam propagations are effectively controlled by the illumination time. Under saturated nonlinearity, the beam intensity maintains the soliton profile at the output section, and its propagation direction is modulated by the beam amplitude. Moreover, the temporal behavior of Airy beam interactions varies greatly with illumination time, especially for the in-phase case. Breathing solitons and parallel soliton pairs are produced in-phase and out-of-phase, respectively. These results are potentially useful in all-optical device applications. ? 2019 Elsevier B.V.Accession Number: 20191606799890 -
Record 451 of
Title:High power semiconductor laser lifetime prediction and failure analysis based on Weibull and Log-normal distribution
Author(s):Nie, Zhiqiang(1); Wang, Mingpei(1,2); Sun, Yubo(1,2); Li, Xiaoning(3); Wu, Di(3)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 48 Issue: DOI: 10.3788/IRLA201948.S105003 Published: April 25, 2019Abstract:The accelerated aging test of 60 W (CW mode) 808 nm indiumpackaged conductively cooled single bar high power semiconductor laser with constant current under three different temperatures was analyzed by Weibull and Lognormal distributions models, respectively. The characteristic lifetime and statistical average lifetime of the device under all the tempertures including room temperature were calculated in Weibull distribution analysis, and it is found that for early failure test, the shape parameter is less than 1, and the calculation error of mathematical average lifetime is larger, which is not as good as statistical average lifetime. In Lognormal distribution analysis, the medium lifetime and statistical average lifetime under all the tempertures are calculated. It is found that for early failure test, the logarithmic standard deviation is larger and creates larger error of statistical average lifetime. It means that Lognormal distribution mode is not suitable for lifetime estimation of early failure device. Finally failure analysis of accelerated lifetime devices is carried out. ? 2019, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.Accession Number: 20192306999652 -
Record 452 of
Title:Hyperspectral Image Denoising by Fusing the Selected Related Bands
Author(s):Zheng, Xiangtao(1); Yuan, Yuan(1); Lu, Xiaoqiang(1)Source: IEEE Transactions on Geoscience and Remote Sensing Volume: 57 Issue: 5 DOI: 10.1109/TGRS.2018.2875304 Published: May 2019Abstract:Hyperspectral images (HSIs) convey more useful information than RGB or gray images, which are widely used in many remote sensing tasks. In real scenarios, HSIs are inevitably corrupted by noise because of sensors' imperfectness or atmospheric influence. Recently, many HSI denoising methods have been proposed to utilize the interband information between different spectral bands. However, these methods regard the HSI as a whole and treat the different spectral bands with the same noise level. In fact, the noise levels in different bands are different. Especially, only few certain bands are corrupted by noise, named the target noised bands. Under this circumstance, an HSI denoising method is proposed by considering the band relationship and different noise levels. The target noised bands are adaptively denoised by fusing some selected bands. Specifically, some related but quality superior bands are selected according to the target noised bands. Then, the target noised bands can be denoised by fusing the selected related bands. Experimental results show that the proposed method achieves considerable performances in comparison with several state-of-the-art hyperspectral denoising methods. ? 1980-2012 IEEE.Accession Number: 20184606073332 -
Record 453 of
Title:Linear space-variant optical cryptosystem via Fourier ptychography
Author(s):Pan, An(1,2); Wen, Kai(3); Yao, Baoli(1)Source: Progress in Biomedical Optics and Imaging - Proceedings of SPIE Volume: 10887 Issue: DOI: 10.1117/12.2509001 Published: 2019Abstract:Optical cryptography has attracted extensive interest because of the inherent nature of parallel and multidimensional capability of optical information processing compared with computer cryptography. However, the linear space-invariant (LSI) cryptosystems are easy to be simulated and may be vulnerable to different attacks. To resist attacks, several phasetruncated Fourier transforms based asymmetric cryptosystem are proposed to utilize the nonlinear operations in the LSI system, but they are proved to be vulnerable due to the inherent nature of LSI system. Notice that several works misunderstand the concept of nonlinear operations to the nonlinear systems. But the nonlinear systems are not easy to be achieved. Herein, an optical cryptosystem based on Fourier ptychography (FP) with double random phase masks is proposed. The encryption process cannot be precisely simulated but only by optical experiment due to the vignetting effect, which is linear space-variant (LSV) and can act as an one-way function from the perspective of optics purely and guarantee the security of our system. In addition, the encryption for a high resolution, large field-of-view and complexvalued image is achievable. Optical experiments are presented to prove the validity and the security of the proposed system. Our method would give more insights to separate the optical cryptography from computer cryptography in nature. ? 2019 SPIE.Accession Number: 20192307011885 -
Record 454 of
Title:Influence of Zirconium Salt Materials on the Structure and Properties of LiZr2(PO4)3 Lithium Ion Solid Electrolyte
Author(s):Li, Wenlong(1,2); Liu, Huan(1,2); Yuan, Kang(1,2); Yang, Liqing(1); Zhou, Qianqian(1); Wang, Haojing(1); Zhang, Hong(1)Source: Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering Volume: 48 Issue: 4 DOI: null Published: April 1, 2019Abstract:Samples of LiZr2(PO4)3 compound with pure phase, adopting the method of solid phase and liquid phase method, were obtained by pressureless sintering from different zirconium salt raw materials. And LiZr2(PO4)3 Li-ion solid electrolytes were characterized through X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical impedance (EIS). Analyzing the results of the test, the influence of different zirconium salt raw materials on the structure and performance of LiZr2(PO4)3 solid electrolytes was studied. The results show that the room-temperature stable α-LiZr2(PO4)3 (rhombohedral phase) was prepared from zirconium acetate. While synthetic LiZr2(PO4)3 prepared from the other three kinds of zirconium salt raw materials exists in triclinic phase. Rhombohedral phase LiZr2(PO4)3 lithium ion solid state electrolyte sample prepared from different zirconium raw materials shows the highest total conductivity of 2.25×10-5 S/cm, and the lowest activation energy of 0.28 eV. ? 2019, Science Press. All right reserved.Accession Number: 20192907192633 -
Record 455 of
Title:Double-dressing tri and quad-photon correlations in spontaneous six and eight-wave mixing
Author(s):Li, Yameng(1); Feng, Yuan(1); Li, Wei(1); Li, Kangkang(1); Liu, Yang(2); Lan, Yuwei(1); Zhang, Yanpeng(1)Source: Physica Scripta Volume: 94 Issue: 10 DOI: 10.1088/1402-4896/ab1abb Published: August 2, 2019Abstract:The generation of a nonclassical multi-photon has aroused renewed interest in recent years. Here, we propose a new method to generate tri-photon and quad-photon correlations in time via a double-dressing spontaneous six-wave mixing and eight-wave mixing process in an atomic ensemble, respectively. When we only consider the nonlinear optical response, the coincidence counts of tri and quad photon serves as damped coherent Rabi oscillation. The coincident count of tri (quad) photon contains three (four) conditional two-photon correlation with 10 or 30 (26, 28 or 38) periods, corresponding to 11 or 19 (18 or 20) modes. These mode and periods of tri and quad photon result from destructive interference from the possible 4 or 8 six wave and 18 eight wave coherent channels, respectively. In addition, for tri-photon, the greater double-dressing field strength is, the fewer the number of periods are. The coherent times are also controlled by the double-dressing effect. Such results have potential applications in multi-mode quantum communication and quantum network. ? 2019 IOP Publishing Ltd.Accession Number: 20194507649482 -
Record 456 of
Title:Two-dimensional simulation of dielectric barrier discharge with ring electrodes at atmospheric pressure
Author(s):Wang, Jing(1,2); Lei, Bingying(1,2); Li, Jing(1,2); Xu, Yonggang(3); Zhang, Jingyue(1,4); Tang, Jie(1,2); Wang, Yishan(1,2); Zhao, Wei(1,2); Duan, Yixiang(1,5)Source: Physics of Plasmas Volume: 26 Issue: 1 DOI: 10.1063/1.5077079 Published: January 1, 2019Abstract:A two-dimensional fluid model was used to investigate the characteristics of helium dielectric barrier discharge (DBD) equipped with ring electrodes at atmospheric pressure. Simulation results show that the transition of discharge also exists as the traditional parallel-plate DBD. The discharge mode translates from the Townsend mode to the glow mode during the rising phase and returns to the Townsend mode in the falling phase of the discharge. Meanwhile, symmetric discharge current and current densities at different radial positions are observed in each cycle, and the current density peak at the radial center of the ring electrode is always higher than that at other positions. In addition, the charged particles follow a periphery-advantage spatial distribution, and the relative temporal variation of charged particles is faster in the periphery than in the central region because of the higher electric field existing there. Moreover, the density of surface charges assembled in the periphery changes faster than that in the central region of the upper dielectric barrier and exhibits an uneven periphery-advantage distribution, which is also ascribed to the higher electric field in the periphery resulted from the ring electrode configuration. Comparing the ring electrode DBD with the traditional one indicates that an inverse discharge structure is observed between the two electrode configurations. ? 2019 Author(s).Accession Number: 20190406407392