2019
2019
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Record 397 of
Title:Auxiliary structure of nano-pinnacle prepared on silicon substrate: Improving the emission intensity by 9 times in SSI-LEDs
Author(s):Liu, Lingguang(1); Wang, Yaogong(1); Lin, Yuanyuan(1); Zhang, Xiaoning(1); Kuo, Yue(2); Tian, Jinshou(3,4)Source: Materials Science in Semiconductor Processing Volume: 93 Issue: DOI: 10.1016/j.mssp.2019.01.010 Published: April 2019Abstract:Auxiliary structure of nano-pinnacle is prepared on silicon substrate of SSI-LEDs device, and the micro-structure properties, electrical and optical characteristics of the proposed structure device are investigated. Non-uniform size and geometry of nano-pinnacles are prepared by wet-etching, and the most frequent geometry is ~230 × 140 nm pyramids. With help of the nano-pinnacle structure, the electric field strength distributed on treated surface of the nano-pinnacle sample is enhanced by ~4 times, resulting in the increase of the density of conductive paths by 3.6 times. By exploring the electrical and optical results, the onset voltage of light emission is decreased by 60% from ? 7.6 V to ? 3.4 V, and the emission intensity and efficiency are improved by ~9 times and ~8 times, respectively compared with the traditional structure device of SSI-LEDs. ? 2019 Elsevier LtdAccession Number: 20190306381862 -
Record 398 of
Title:Nanosecond level passively Q-switched Ti:Sapphire laser using MoS2 as a saturable absorber
Author(s):Sun, Zhe(1); Li, Guangying(1); Liu, Huan(1); Cheng, Guanghua(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11052 Issue: DOI: 10.1117/12.2521960 Published: 2019Abstract:A molybdenum disulfide (MoS2) saturable absorber (SA) solution is fabricated by liquid-phase exfoliation (LPE) method. By using the MoS2-SA solution, a compact diode-pumped passively Q-switched Ti:Sapphire laser has been demonstrated. The minimum short pulse width is 3.7 ns and the maximum pulse energy is 16.2 μJ at 1 kHz repetition rate. Our results show that MoS2-SA solution can be developed as an effective saturable absorber to achieve nanosecond pulse laser in the infrared range. ? 2019 SPIE.Accession Number: 20190806534743 -
Record 399 of
Title:Quantum-enhanced metal target detection based on quantum illumination
Author(s):Li, Lifei(1); Kang, Yan(1); Wang, Biao(1); Wu, Yangcao(1); Zhang, Tongyi(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11209 Issue: DOI: 10.1117/12.2549965 Published: 2019Abstract:We report the quantum-enhanced metal target detection based on quantum illumination, and experimentally verified that quantum illumination still helps low-reflectivity target detection in photon loss scenarios. The results show that the signal-to-noise ratio and target recognition ability of the quantum detection system are more than 10 times stronger than those of the classical detection under the same thermal noise conditions. We believe that the photon-counting based QI protocol, for its robustness to noise and losses, has a huge potentiality to promote the usage of quantum correlated light in real environments. ? 2019 SPIE.Accession Number: 20200508093407 -
Record 400 of
Title:Modeling and optimization of actively Q-switched 2.8 μm Er3+-doped ZBLAN fiber laser
Author(s):Shen, Yanlong(1,2,3,4); Wang, Yishan(1,5); Tao, Mengmeng(3); Luan, Kunpeng(3); Zhu, Feng(3); Si, Jinhai(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 11046 Issue: DOI: 10.1117/12.2523927 Published: 2019Abstract:A theoretical model based on rate equations for actively Q-switched Er3+-doped ZBLAN fiber laser is built. The operation behaviors and output characteristics of the actively Q-switched fiber laser at 2.8 μm are analyzed. Effects of some important laser parameters, such as pump power levels, reflectivity of the laser output coupler, fiber lengths, Er concentrations, etc., on laser output were investigated. The model and simulating results are useful for design and optimization of actively Q-switched fiber laser at 2.8-μm region. ? COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.Accession Number: 20192106969839 -
Record 401 of
Title:Reconstructing a scattered image via spatial cross-phase modulation instability in partially incoherent beams
Author(s):Han, Jing(1,3); Liu, Hongjun(1,2); Huang, Nan(1); Wang, Zhaolu(1); Zhang, Yongbin(1,3); Chi, Jiao(1,3)Source: Applied Physics Express Volume: 12 Issue: 1 DOI: 10.7567/1882-0786/aaf713 Published: January 1, 2019Abstract:A technology of stochastic resonance is proposed for reconstructing a scattered image, which is based on the spatial cross-phase modulation instability between partially incoherent beams. An original model is built to describe the nonlinear coupling, in which the energy directionally transfers from the background noise to the weak signal. Through reasonably controlling the noise statistics and coupling strength in a nonlinear medium, the profile and details of the underlying image dominated by the scattering noise are efficiently recovered with remarkable cross-correlation gains. This work suggests an efficient method of image detection and holds potential for broader imaging applications in dynamic scattering environments. ? 2019 The Japan Society of Applied Physics.Accession Number: 20190306378604 -
Record 402 of
Title:Er/Yb Codoped double clad fiber modal interferometer and its application as fiber sensor
Author(s):Yang, Hening(1,2,3,4); Dong, Bo(1,4); Zhao, Wei(1,4); Chen, Enqing(2); Wang, Yishan(1,4); Si, Jinhai(3)Source: Journal of Lightwave Technology Volume: 37 Issue: 11 DOI: 10.1109/JLT.2018.2875539 Published: June 1, 2019Abstract:An Er/Yb codoped double clad fiber (EYDF) modal interferometer and its application as fiber sensor are proposed and demonstrated. It has the single mode fiber (SMF)-EYDF-SMF structure with two asymmetrical splice joints. The MI is sensitive to refractive index (RI) and temperature. Experimental results show that the pump power can tune its operation wavelength, and the higher power will lead to the more redshift of its transmission spectrum. What's more, appropriate change of RI can improve the wavelength tuning range induced by pump power. Moreover, its RI and thermal sensitivities are pump power dependent, and higher pump power will lead to its lower RI sensitivity and lower thermal sensitivity. ? 2018 IEEE.Accession Number: 20184205949323 -
Record 403 of
Title:Cascaded fiber up-Taper modal interferometer and its application as fiber sensor
Author(s):Dong, Shandong(1,2); Dong, Bo(3); Yu, Changyuan(4); Guo, Yongxin(1,2)Source: Journal of Lightwave Technology Volume: 37 Issue: 11 DOI: 10.1109/JLT.2018.2878040 Published: June 1, 2019Abstract:A cascaded fiber up-Taper interferometer (CFI) is proposed and demonstrated analytically and experimentally. The sensor head of the CFI consists of two cascaded miniaturized fiber up-Taper modal interferometers (MMIs). Sensing principle of the CFI is derived based on the transmission matrix method. Conclusions have been achieved that cascading MMIs can effectively improve its thermal sensitivity while strain sensitivity is reduced compared with that of the single MMI. Experimentally, thermal sensitivity of the CFI can reach 112.9 pm/°C, and almost two times as big as that of the single MMI. In contrast, its strain sensitivity is only-0.4 pm/μ?, which is only 2/5 as small as that of the single MMI. ? 1983-2012 IEEE.Accession Number: 20184406021614 -
Record 404 of
Title:Master oscillator pulse nonlinear amplifier system based on all polarization-maintaining fiber
Author(s):Zhang, Tong(1); Zhang, Wei-Guang(1); Cai, Ya-Jun(2); Hu, Xiao-Hong(2); Feng, Ye(2); Wang, Yi-Shan(2); Yu, Jia(1)Source: Wuli Xuebao/Acta Physica Sinica Volume: 68 Issue: 23 DOI: 10.7498/aps.68.20190925 Published: December 5, 2019Abstract:The erbium-doped fiber oscillators, especially mode-locked fiber oscillators for generating femtosecond pulses, cannot meet the requirements for most of modern industrial applications because they are resticted by the low power and the limited wavelength range. In order to solve this problem, lots of efforts have been made both theoretically and experimentally, to improve the chirped pulse amplification (CPA) technology. The emergence of CPA technology greatly enhances the energy of laser pulses. The broadening and compressing of the laser pulses are both always dependent on the improving of spatial optical components, such as grating pairs. However, the use of this kind of method can increase the complexity of the amplification system to a certain extent. This may be an essential reason why more and more researchers pay attention to all fiber amplification system. In this paper, the master oscillator pulse nonlinear amplifier system based on all polarization- maintaining fiber is proposed, which is mainly composed of an oscillator based on the semiconductor saturable absorption mirror and linear cavity, a two-stage amplification and a pulse compressor constructed by a single-mode conductive fiber with anomalous dispersion. Using this system, we obtain ultrashort laser pulses in the 1.5 nm band whose pulse width equals 44 fs and single pulse energy reaches about 1 nJ. The system is not only compact and miniaturized but also stable and reliable due to the all polarization-maintaining fiber. Subsequently, an MgO doped periodically poled lithium niobite crystal with a thickness of 1 mm is used to implement frequency doubling. The pulses from the system are accurately focused on a position where the crystal polarization period is 19.8 μm with help of some wave plates and lenses. Adjusting the optical path reasonably and optimizing colliminated focusing parameters, the double-frequency pulse output with certral wavelength of 779 nm and average power of 60 W is obtained, in which the conversion efficiency reaches 30%. The result shows that the master oscillator pulse nonlinear amplifier system based on all polarization maintaining fiber can produce satisfactory ultrashort pulses. It is a new idea for generating the ultrashort femtosecond pulses in the near-infrared band. ? 2019 Chinese Physical Society.Accession Number: 20200408064419 -
Record 405 of
Title:Retrieval of non-sparse object through scattering media beyond the memory effect
Author(s):Zhou, Meiling(1); Pan, An(1); Li, Runze(1); Liang, Yansheng(2); Min, Junwei(1); Peng, Tong(1); Bai, Chen(1); Yao, Baoli(1)Source: arXiv Volume: Issue: DOI: null Published: July 20, 2019Abstract:Optical imaging through scattering media is a commonly confronted with the problem of reconstruction of complex objects and optical memory effect. To solve the problem, here, we propose a novel configuration based on the combination of ptychography and shower-curtain effect, which enables the retrieval of non-sparse samples through scattering media beyond the memory effect. Furthermore, by virtue of the shower-curtain effect, the proposed imaging system is insensitive to dynamic scattering media. Results from the retrieval of hair follicle section demonstrate the effectiveness and feasibility of the proposed method. The field of view is improved to 2.64mm. This present technique will be a potential approach for imaging through deep biological tissue. Copyright ? 2019, The Authors. All rights reserved.Accession Number: 20200211630 -
Record 406 of
Title:Intrinsic weight learning approach for multi-view clustering
Author(s):Nie, Feiping(1); Li, Jing(1); Li, Xuelong(2)Source: arXiv Volume: Issue: DOI: null Published: June 20, 2019Abstract:Exploiting different representations, or views, of the same object for better clustering has become very popular these days, which is conventionally called multi-view clustering. Generally, it is essential to measure the importance of each individual view, due to some noises, or inherent capacities in description. Many previous works model the view importance as weight, which is simple but effective empirically. In this paper, instead of following the traditional thoughts, we propose a new weight learning paradigm in context of multi-view clustering in virtue of the idea of re-weighted approach, and we theoretically analyze its working mechanism. Meanwhile, as a carefully achieved example, all of the views are connected by exploring a unified Laplacian rank constrained graph, which will be a representative method to compare with other weight learning approaches in experiments. Furthermore, the proposed weight learning strategy is much suitable for multi-view data, and it can be naturally integrated with many existing clustering learners. According to the numerical experiments, the proposed intrinsic weight learning approach is proved effective and practical to use in multi-view clustering. Copyright ? 2019, The Authors. All rights reserved.Accession Number: 20200290742 -
Record 407 of
Title:A general framework for edited video and raw video summarization
Author(s):Li, Xuelong(1); Zhao, Bin(2); Lu, Xiaoqiang(1)Source: arXiv Volume: Issue: DOI: null Published: April 24, 2019Abstract:In this paper, we build a general summarization framework for both of edited video and raw video summarization. Overall, our work can be divided into three folds: 1) Four models are designed to capture the properties of video summaries, i.e., containing important people and objects (importance), representative to the video content (representativeness), no similar key-shots (diversity) and smoothness of the storyline (storyness). Specifically, these models are applicable to both edited videos and raw videos. 2) A comprehensive score function is built with the weighted combination of the aforementioned four models. Note that the weights of the four models in the score function, denoted as property-weight, are learned in a supervised manner. Besides, the property-weights are learned for edited videos and raw videos, respectively. 3) The training set is constructed with both edited videos and raw videos in order to make up the lack of training data. Particularly, each training video is equipped with a pair of mixing-coefficients which can reduce the structure mess in the training set caused by the rough mixture. We test our framework on three datasets, including edited videos, short raw videos and long raw videos. Experimental results have verified the effectiveness of the proposed framework. Copyright ? 2019, The Authors. All rights reserved.Accession Number: 20200428568 -
Record 408 of
Title:Simulation and analysis of the self-focusing phenomenon of high intensity laser systems in nonlinear medium
Author(s):Li, Dongdong(1); Zhang, Pengbo(1); Zhang, Wenwen(1); She, Jiangbo(2)Source: Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering Volume: 48 Issue: 7 DOI: 10.3788/IRLA201948.0706003 Published: July 25, 2019Abstract:Based on high intensity laser systems theory and self-focusing research, the nonlinear medium under the beam transmission process was described using the beam propagation method and ray tracing method. Besides, it was found that some ways were suitable for nonlinear medium, such as Adams method under the ray tracing method and recovery algorithm based on gradient information of intensity distribution. Finally, the simulation results revealed the relationship between the light intensity and these factors, including lens thickness, the refractive index of medium, the lens curvature radius and the radius of the incident beam. And combined with optical design software, it not only reflected the relationship between the product of the refractive index and the light intensity and the focus position changes, but also the results of image quality intuitively through the data of spot diagram. And two kinds of main optical methods, the ray tracing method and the beam propagation method, were made for the comparative analysis. According the simulation results, it could be determined that bits of the system was easily affected by self-focusing, so the size of certain parameters could be improved, the adverse effect could be reduced and eliminated, and an optimal method which was suitable for strong laser system could be found. ? 2019, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved.Accession Number: 20193807445304