2021
2021
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Record 289 of
Title:Two-dimensional optical gap solitons and vortices in a coherent atomic ensemble loaded on optical lattices
Author(s):Chen, Zhiming(1,2,3); Zeng, Jianhua(2)Source: Communications in Nonlinear Science and Numerical Simulation Volume: 102 Issue: DOI: 10.1016/j.cnsns.2021.105911 Published: November 2021Abstract:Coherent atomic systems, e.g., resonantly cold atomic gases within which electromagnetically induced transparency (EIT) operates, have recently received great attention, because of their remarkable scientific properties and pivotal implications. Light behavior in such systems governed by various potentials is a new and interesting research focus, but missing literally report on two-dimensional (2D) localized gap modes in coherent atomic systems loaded on optical lattices. We survey such issue in a coherent atomic gas inside where the EIT turns on, trapped by 2D optical lattices—constituted by counter-propagating far-detuned Stark laser fields, in the framework of nonlinear Schr?dinger equation derived from Maxwell-Bloch equations. Using the linear stability analysis and direct perturbed evolution we address the formation, property, and stability of 2D localized gap modes of two types, gap solitons and gap vortices, in forbidden band gaps of the underlying linear Bloch-wave spectrum. The former mode is fundamental gap solitons, and the latter belongs to higher-order gap solitons with embedded topological charge. Our results are helpful not only for in-depth understanding of soliton dynamics in coherent atomic ensemble loaded on periodic potentials, but also for laying the groundwork for forthcoming applications in optical communications and quantum information processing. ? 2021 Elsevier B.V.Accession Number: 20212510518780 -
Record 290 of
Title:Laser collimation beam expansion design based on the Galileo structure
Author(s):He, Xuan(1,2); Bai, Jianming(1)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12065 Issue: DOI: 10.1117/12.2606813 Published: 2021Abstract:Starting from the collimated beam to be solved by the lighting system, based on the Gaussian optical theory, the transformation of Gaussian beam through the lens is deduced, the principle of large magnification collimating and expanding beam system is analyzed, and the design of collimating and expanding beam system changing the laser beam diameter and divergence angle is realized. It is verified by simulation, which meets the requirements of the lighting system for parallel light incidence. ? 2021 SPIE.Accession Number: 20220211437960 -
Record 291 of
Title:Aerial Infrared Object Tracking via an improved Long-term Correlation Filter with optical flow estimation and SURF matching
Author(s):Wang, Xiaotian(1); Zhang, Kai(1); Zhang, Ximing(2); Li, Shaoyi(1); Yan, Jie(1)Source: Infrared Physics and Technology Volume: 116 Issue: DOI: 10.1016/j.infrared.2021.103790 Published: August 2021Abstract:At present, there are many excellent algorithms in the field of visual object tracking. The correlation filter algorithms are more suitable for infrared object tracking, for the tracking performance is the best. Especially, the long-term correlation tracking has received much attention, owing to its ability to handle the problems of universal tracking (e.g., slight deformation, small-displacement motion, partial occlusion and out of view). However, there are three imperfections such that it fails to solve the problem of rapid motion, it cannot cope with the problem of boundary effect perfectly, and it has poor tracking effect in the case of severe occlusion and severe deformation. Aiming at the problem of rapid motion, the FlowNet 2.0 is introduced to accomplish optical flow estimation, offering motion information and predicting trajectory change process. Aiming to address the concern of boundary effect perfectly, the adjustable Gaussian window is effective to separate the object and the background, improving classifier discrimination. Aiming at the issue of poor tracking effect in the case of severe occlusion and severe deformation, the SURF feature-based matching method is effective to accurately track object and improve the infrared object tracking performance. In addition, the ratio between average peak-to-correlation energy (APCE) and its historical average, as a further complement of maximum response, is introduced to achieve the online updating mechanism, jointly determining whether the tracker needs to be updated, the SURF matching needs to be carried out or the tracker needs to be initialized by re-detector. Our algorithm is validated on synthetic infrared aerial object image sequences, real infrared thermal aerial object image sequences and a public database named AMCOM FLIR respectively. The extensive experimental testify that our improved approach achieves an optimal effect for aerial infrared object tracking in terms of precision plot, success plot and speed. ? 2021Accession Number: 20212510523132 -
Record 292 of
Title:Temporal Constraint Background-Aware Correlation Filter with Saliency Map
Author(s):Liao, Jiawen(1); Qi, Chun(2); Cao, Jianzhong(1)Source: IEEE Transactions on Multimedia Volume: 23 Issue: DOI: 10.1109/TMM.2020.3023794 Published: 2021Abstract:Correlation filter (CF) based trackers have recently drawn great attention in visual tracking community due to their impressive performance, and computational efficiency on benchmark datasets. However, the performance of most existing trackers using correlation filter is hampered by two aspects: i) Included background information in the selected rectangular target patch is considered as part of the target, and they are treated as important as the real target in training new filter model, it causes the filter easily drift when target shape changes dramatically. ii) Existing filters use a moving average operation with an empirical weight to update the filter model in each frame, such per frame adaptation constantly introduces new information of the target patch, but never consider the consistence of the historical information, and the newly obtained one, further increases the risk of drifting. This paper presents a new framework including saliency map, and a novel CF regression model. We reformulate the original optimization problem, and provide a closed form solution for multidimensional features which is solved efficiently using alternating direction method of multipliers (ADMM), and accelerated using Sherman-Morrison lemma, our algorithm as a new framework can be easily integrated into CF base trackers to boost their tracking performance. We perform comprehensive experiments on five benchmarks: OTB-2015, VOT2016, VOT2018, UAV123, and TempleColor-128. Results show that the proposed method performs favorably against lots of state-of-the-art methods with a speed close to real-time. Our method with deep features performs much better on all 5 datasets. ? 1999-2012 IEEE.Accession Number: 20214010966294 -
Record 293 of
Title:Continuous Blood Pressure Monitoring Based on Wearable Optical Fiber Interferometry Wristband
Author(s):Chen, Xiao(1); Xu, Wei(2,3); Dong, Bo(4); Yu, Changyuan(6,7); Zhao, Wei(2,3,5); Wang, Yishan(2,3,5); Sun, Wenye(8)Source: 2021 Opto-Electronics and Communications Conference, OECC 2021 Volume: Issue: DOI: null Published: 2021Abstract:We demonstrate a wearable optical fiber interferometry wristband which is used for continuous blood pressure monitoring. The pulse transit time extracted from the pulse wave can be used to established the blood pressure estimation model. OCIS codes: (060.2370) Fiber optical sensors; (000.1430) Biology and medicine. ? 2021 OSA.Accession Number: 20224012832621 -
Record 294 of
Title:Modulated optical signal detection based on cross-correlation algorithm
Author(s):Zeng, Ke(1,2); Han, Junfeng(2); Wang, Haitao(2); Wang, Chen(2); Xie, Xiaoping(2)Source: Proceedings of SPIE - The International Society for Optical Engineering Volume: 12060 Issue: DOI: 10.1117/12.2606529 Published: 2021Abstract:With the development of the information age, the transmission rate and transmission capacity of information continue to increase. As a wireless communication method to achieve high bit rate communication, space laser communication plays an increasingly obvious role in global communications. In the current space laser communication system, the optical communication terminal uses a detector to detect the position of the received optical signal, and then the servo mechanism on it performs facula tracking. However, when a four-quadrant detector (4QD) is used to detect optical signal, the received optical signal generally contains three main types of noise, which are background radiation noise, shot noise and thermal noise. These three kinds of noise can be equivalent to Gaussian white noise. In this paper, a single-frequency cosine signal is used to modulate the intensity of the optical signal received by the 4QD, and then the modulated optical signal is detected by a spectrum analysis method based on the cross-correlation algorithm. This method reduces the relative error of the spectral line amplitude when the SNR is -5dB from 2.23% to 0.88%, and reduces the relative error of the spectral line amplitude when the SNR is -20dB from 17.6% to 5.49%. Therefore, this method can well suppress Gaussian white noise and improve the detection accuracy of modulated optical signal under extremely low SNR conditions. ? 2021 SPIE.Accession Number: 20220211446432 -
Record 295 of
Title:Study on the performance of polarization maintaining fiber temperature sensor based on tilted fiber grating
Author(s):Zhao, Jun(1,3); Wang, Hushan(2); Sun, Xiaohan(1)Source: Measurement: Journal of the International Measurement Confederation Volume: 168 Issue: DOI: 10.1016/j.measurement.2020.108421 Published: 15 January 2021Abstract:A novel functional-type high integration polarization interference fiber temperature sensor based on 45° tilted fiber Bragg grating in-fiber polarizer (TFBG-PIF-TS) is proposed. The accuracy, resolution, stability, linearity and sensitivity of the prototype are tested and compared with PT100, 18B20 as well as polarizing plate based polarization interferometric fiber temperature sensor (PP-PIF-TS). The feasibility of the scheme in the transformer winding temperature monitoring is verified. The results show that the accuracy and resolution of TFBG-PIF-TS reach ±0.1 °C and 0.01 °C respectively, which has higher resolution, better integration and reliability, and has simple structure, strong anti-vibration and anti-electromagnetic interference abilities. Therefore, the proposed scheme can meet the needs of high voltage, strong magnetic field and other passive precise temperature measurement occasions. ? 2020 Elsevier LtdAccession Number: 20203809183985 -
Record 296 of
Title:Continuous blood pressure monitoring based on wearable optical fiber interferometry wristband
Author(s):Chen, Xiao(1); Xu, Wei(2,3); Dong, Bo(4); Yu, Changyuan(6,7); Zhao, Wei(2,3,5); Wang, Yishan(2,3,5); Sun, Wenye(8)Source: Optics InfoBase Conference Papers Volume: Issue: DOI: null Published: 2021Abstract:We demonstrate a wearable optical fiber interferometry wristband which is used for continuous blood pressure monitoring. The pulse transit time extracted from the pulse wave can be used to established the blood pressure estimation model. ? OSA 2021, ? 2021 The Author(s)Accession Number: 20214811222111 -
Record 297 of
Title:Comprehensive risk assessment of transmission lines affected by multi-meteorological disasters based on fuzzy analytic hierarchy process
Author(s):Han, Binbin(1); Ming, Zhengfeng(1); Zhao, Yuhu(1); Wen, Tao(1); Xie, Meilin(2)Source: International Journal of Electrical Power and Energy Systems Volume: 133 Issue: DOI: Published: December 2021Abstract:nullAccession Number: 20212510529574 -
Record 298 of
Title:Optical ranging system based on multiple pulse train interference using soliton microcomb
Author(s):Zheng, Jihui(1); Wang, Yang(2,3); Wang, Xinyu(2,3); Zhang, Fumin(1); Wang, Weiqiang(2); Ma, Xin(1); Wang, Jindong(1); Chen, Jiawei(1); Jia, Linhua(1); Song, Mingyu(1); Yuan, Meiyan(2,3); Little, Brent(2,3); Chu, Sai Tek(4); Cheng, Dong(2,3); Qu, Xinghua(1); Zhao, Wei(2,3); Zhang, Wenfu(2,3)Source: Applied Physics Letters Volume: 118 Issue: 26 DOI: 10.1063/5.0054065 Published: June 28, 2021Abstract:The multiple pulse train interference (MPTI) ranging system takes advantage of the high accuracy and absolute length measurement capability, but traditional scheme has a large measurement dead zone. In this Letter, we propose a MPTI ranging scheme based on chip-based soliton microcomb to achieve high-precision but no dead-zone measurement. The measurement optical path is improved to solve the problem of cross correlation interference fringe overlap, and a peak fitting algorithm is employed to further improve the measurement accuracy of the system. Using a commercial He-Ne interferometer, a 384?nm precision is obtained in 1.5 m distance measurements. Advantages of the simple optical path, high precision, and no measurement dead zone are expected to realize on-chip integration and provide a solution for precision measurement. ? 2021 Author(s).Accession Number: 20212810608721 -
Record 299 of
Title:Using Landsat-8 imagery and Generative Adversarial Network for Glacial Lakes Mapping in High Mountain Regions
Author(s):Zhao, Hang(1,2); Liu, Xuebin(1,2); Wang, Shuang(1,2)Source: Proceedings of 2021 IEEE 2nd International Conference on Information Technology, Big Data and Artificial Intelligence, ICIBA 2021 Volume: Issue: DOI: 10.1109/ICIBA52610.2021.9687901 Published: 2021Abstract:As an essential resource in High Mountain Regions (HMR), evaluating the glacial lake dynamics is of great significance to explore the impacts of climate changes and predict the risks of Glacial Lake Outburst Floods (GLOFs). However, complicated and laborious methods for glacial lake mapping are unpractically applied in automatically monitoring glacial lakes at a large-scale region. In this work, we explored the mapping efficiency of glacial lakes by combing Generative Adversarial Networks and multi-level feature pyramid (GANMFP) in HMR. We first sampled the image patches containing glacial lakes from Landsat-8 raw data to evaluate the model performance. Totally, 6583 patches with 256x256x7 pixels are randomly cropped from 62 Landsat-8 images. Then we employed these data to train and test the GAN model, which integrated a multi-level feature fusion module in generator and a Resnet-152 networks in discriminator. From the validation results and result visualization, our method achieved good performances in Precision (88.42), Recall (59.61), and Overall Accuracy (99.28), which shows excellent potential in glacial lake mapping at a large-scale region. ? 2021 IEEE.Accession Number: 20221311844088 -
Record 300 of
Title:Beat-to-Beat Heart Rate Estimation from MZI-BCG Signal Based on Hierarchical Clustering
Author(s):Zeng, Huaili(1); Xu, Wei(2,3); Dong, Bo(4); Yu, Changyuan(6,7); Zhao, Wei(2,3,5); Wang, Yishan(2,3,5); Sun, Wenye(8)Source: 2021 Opto-Electronics and Communications Conference, OECC 2021 Volume: Issue: DOI: null Published: 2021Abstract:An algorithm is proposed in this paper to estimate the beat-to-beat heart rate based on BCG signal derived from Mach-Zehnder Interferometer with hierarchical clustering and matched-filtering. ? 2021 OSA.Accession Number: 20224012832623