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High-performance optical chirp chain BOTDA by using a pattern recognition algorithm and the differential pulse-width pair technique

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Photonics Research 2019年第6期7卷 652-658页

作者： BENZHANG WANG BAOHUA FAN dengwang zhou CHAO PANG YUE LI DEXIN BA YONGKANG DONG National Key Laboratory of Science and Technology on Tunable Laser Harbin Institute of Technology Harbin 150001 China The 29th Research Institute of China Electronics Technology Group Corporation Chengdu 610036 China

Optical chirp chain Brillouin optical time-domain analysis(OCC-BOTDA) has the capabilities of fast measurement, high Brillouin threshold, and freedom from the nonlocal effect;at the same time, however, it also has problems introduced by transient stimulated Brillouin scattering. The influence of the transient interaction is reflected as the broadened asymmetric Brillouin spectrum, the ghost peak, and the frequency shift of the main peak. This introduces difficulty in computing the fiber Brillouin frequency shift with good measurement accuracy. Besides, the OCC modulation causes additional noise due to the uneven amplitude response for different frequency components. In this work, we propose a high-performance OCC-BOTDA using the principal component analysis(PCA) based pattern recognition algorithm and differential pulse-width pair(DPP) *** building the Brillouin spectrum database(i.e., all patterns), the fiber intrinsic Brillouin frequency shift can be recognized by the PCA algorithm from a nonstandard Brillouin spectrum profile, resulting in good measurement accuracy. Meanwhile, the DPP technique, subtracting between two Brillouin signals generated by two wide-width pump pulses, is utilized to reduce the OCC modulation noise and avoid the pulse self-phase modulation effect in long-range BOTDA sensing. In the experiment, a temperature measurement with 1.3 MHz measurement precision, 4 m spatial resolution, and 5 s measurement time is achieved over a 100 km single-mode fiber.

关键词： pattern recognition algorithm BOTDA

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High‐sensitivity distributed dynamic strain sensing by combining Rayleigh and Brillouin scattering

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Opto-Electronic Advances 2020年第12期3卷 1-8页

作者： Benzhang Wang Dexin Ba Qi Chu Liqiang Qiu dengwang zhou Yongkang Dong National Key Laboratory of Science and Technology on Tunable Laser Harbin Institute of TechnologyHarbin 150001China

The phase-sensitive optical time-domain reflectometry(φ-OTDR)is a good candidate for distributed dynamic strain sensing,due to its high sensitivity and fast measurement,which has already been widely used in intrusion monitoring,geophysical exploration,*** the frequency scanning basedφ-OTDR,the phase change manifests itself as a shift of the intensity *** correlation between the reference and measured spectra is employed for relative strain demodulation,which has imposed the continuous measurement for the absolute strain ***,the Brillouin optical time domain analysis(BOTDA)allows for the absolute strain demodulation with only one *** this work,the combination of theφ-OTDR and BOTDA has been proposed and demonstrated by using the same set of frequency-scanning optical pulses,and the frequency-agile technique is also introduced for fast measurements.A 9.9 Hz vibration with a strain range of 500 nεhas been measured under two different absolute strains(296.7μεand 554.8με)by integrating the Rayleigh and Brillouin *** sub-micro strain vibration is demonstrated by theφ-OTDR signal with a high sensitivity of 6.8 nε,while the absolute strain is measured by the BOTDA signal with an accuracy of 5.4με.The proposed sensor allows for dynamic absolute strain measurements with a high sensitivity,thus opening a door for new possibilities which are yet to be explored.

关键词： fiber optics sensor Rayleigh scattering Brillouin scattering fast measurement

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Two-dimensional particle-in-cell modeling of blow-off impulse by X-ray irradiation

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Nuclear Science and Techniques 2024年第3期35卷 53-69页

作者： Ruibo Li Jin-Long Jiao Hui Luo Dezhi Zhang dengwang Wang Kai Wang Graduate School of China Academy of Engineering Physics Beijing 100193China Zhejiang Institute of Modern Physics Institute of AstronomySchool of PhysicsZhejiang UniversityHangzhou 310027China National Key Laboratory of Intense Pulsed Radiation Simulation and Effect Northwest Institute of Nuclear TechnologyXi’an 710024China

Space objects such as spacecraft or missiles may be exposed to intense X-rays in outer space,leading to severe *** reinforcement of these objects to reduce the damage caused by X-ray irradiation is a significant *** blow-off impulse(BOI)is a crucial physical quantity for investigating material damage induced by X-ray ***,the accurate calculation of BOI is challenging,particularly for large deformations of materials with complex *** this study,we develop a novel two-dimensional particle-in-cell code,Xablation2D,to calculate BOIs under far-field X-ray *** significantly reduces the dependence of the numerical simulation on the grid *** reliability of this code is verified by simulation results from open-source codes,and the calculated BOIs are consistent with the experimental and analytical results.

关键词： X-ray irradiation Energy deposition Blow-off impulse Particle in cells

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Single-shot BOTDA based on an optical chirp chain probe wave for distributed ultrafast measurement

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Light(Science & Applications) 2018年第1期7卷 718-728页

作者： dengwang zhou Yongkang Dong Benzhang Wang Chao Pang Dexin Ba Hongying Zhang Zhiwei Lu Hui Li Xiaoyi Bao National Key Laboratory of Science and Technology on Tunable Laser Harbin Institute of Technology150001 HarbinChina Department of Optoelectronic Information Science and EngineeringHarbin University of Science and Technology150080 HarbinChina School of Civil Engineering Harbin Institute of Technology150001 HarbinChina Fiber Optics Group Department of PhysicsUniversity of OttawaOttawaON K1N 6N5Canada

Brillouin optical time-domain analysis(BOTDA)requires frequency mapping of the Brillouin spectrum to obtain environmental information(e.g.,temperature or strain)over the length of the sensing fiber,with the finite frequencysweeping time-limiting applications to only static or slowly varying strain or temperature *** solve this problem,we propose the use of an optical chirp chain probe wave to remove the requirement of frequency sweeping for the Brillouin spectrum,which enables distributed ultrafast strain measurement with a single pump *** optical chirp chain is generated using a frequency-agile technique via a fast-frequency-changing microwave,which covers a larger frequency range around the Stokes frequency relative to the pump wave,so that a distributed Brillouin gain spectrum along the fiber is *** strain measurements for periodic mechanical vibration,mechanical shock,and a switch event are demonstrated at sampling rates of 25 kHz,2.5 MHz and 6.25 MHz,*** the best of our knowledge,this is the first demonstration of distributed Brillouin strain sensing with a wide-dynamic range at a sampling rate of up to the MHz level.

关键词： optical pump wave

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Hundred-Joule-level,nanosecond-pulse Nd:glass laser system with high spatiotemporal beam quality

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High Power Laser Science and Engineering 2016年第1期4卷 63-74页

作者： Sensen Li Yulei Wang Zhiwei Lu Lei Ding Yi Chen Pengyuan Du Dexin Ba Zhenxing Zheng Xin Wang Hang Yuan Chengyu Zhu Weiming He Dianyang Lin Yongkang Dong dengwang zhou Zhenxu Bai Zhaohong Liu Can Cui National Key Laboratory of Science and Technology on Tunable Laser Harbin Institute of Technology Research Center of Laser Fusion China Academy of Engineering Physics

A 100-J-level Nd:glass laser system in nanosecond-scale pulse width has been constructed to perform as a standard source of high-fluence-laser science experiments. The laser system, operating with typical pulse durations of 3–5 ns and beam diameter 60 mm, employs a sequence of successive rod amplifiers to achieve 100-J-level energy at 1053 nm at3 ns. The frequency conversion can provide energy of 50-J level at 351 nm. In addition to the high stability of the energy output, the most valuable of the laser system is the high spatiotemporal beam quality of the output, which contains the uniform square pulse waveform, the uniform flat-top spatial fluence distribution and the uniform flat-top wavefront.

关键词： design frequency conversion laser amplifiers laser engineering laser systems light propagation modeling nonlinear optics optimization wavefront correction

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前向受激布里渊散射光纤传感研究进展

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光电工程 2022年第9期49卷 4-24页

作者：李天夫巴德欣周登望任玉丽陈超张洪英董永康哈尔滨理工大学黑龙江省量子调控重点实验室测控技术与通信工程学院哈尔滨工业大学可调谐(气体)激光技术国家级重点实验室哈尔滨工业大学光学工程流动站和空间光学工程研究中心

前向受激布里渊散射(F-SBS)是光纤中重要的三阶非线性效应，是进行外界物质识别和分析研究光纤物理特性的有力手段，成为近年研究的热点。本文通过对光纤中前向受激布里渊散射研究进展的调研和分析，整合了F-SBS的主要理论和传感原理，... 详细信息

前向受激布里渊散射(F-SBS)是光纤中重要的三阶非线性效应，是进行外界物质识别和分析研究光纤物理特性的有力手段，成为近年研究的热点。本文通过对光纤中前向受激布里渊散射研究进展的调研和分析，整合了F-SBS的主要理论和传感原理，回顾了基于相位解调和能量转移探测的F-SBS测量手段，并重点介绍了本地光相位追溯技术、光力时域反射技术和光力时域分析技术等分布式传感技术。随着F-SBS传感器的逐渐实用化，对于F-SBS的高精度、高空间分辨力分布式测量的需求愈发显著，这将是未来光纤中前向受激布里渊散射的主要研究方向。

关键词：前向受激布里渊散射光纤传感光力时域分析非线性光学

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数字素养对大学生就业质量的影响研究

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常州信息职业技术学院学报 2024年第2期23卷 75-80页

作者：周宇寰姚登旺南京城市职业学院江苏南京211200

数字化时代背景下,社会对数字化素养人才的期望和要求不断提高。研究选取数字意识、计算思维、数字化学习与创新、数字社会责任作为数字素养评价指标,选取南京市、杭州市、哈尔滨市355份2022届大学生毕业调查数据,采用结构方程模型探究... 详细信息

数字化时代背景下,社会对数字化素养人才的期望和要求不断提高。研究选取数字意识、计算思维、数字化学习与创新、数字社会责任作为数字素养评价指标,选取南京市、杭州市、哈尔滨市355份2022届大学生毕业调查数据,采用结构方程模型探究数字素养对大学生就业质量的影响和作用机理。结果表明,数字意识、计算思维、数字化学习与创新、数字社会责任4项指标均对大学生就业质量有显著正向影响。高校应当重视大学生数字素养相关课程的开设与教学工作的开展,以期提升学生数字素养,实现高质量就业。

关键词：数字素养大学生就业质量

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Non-destructive and distributed measurement of optical fiber diameter with nanometer resolution based on coherent forward stimulated Brillouin scattering

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Light(Advanced Manufacturing) 2021年第4期2卷 1-12页

作者： Zijie Hua Dexin Ba dengwang zhou Yijia Li Yue Wang Xiaoyi Bao Yongkang Dong National Key Laboratory of Science and Technology on Tunable Laser Harbin Institute of Technology150001 HarbinChina Postdoctoral Research Station for Optical Engineering School of AstronauticsHarbin Institute of TechnologyHarbin 150001China Research Center for Space Optical Engineering School of AstronauticsHarbin Institute of TechnologyHarbin 150001China Fiber Optics Group Department of PhysicsUniversity of OttawaOttawaK1N 6N5Canada

Precise control and measurement of the optical fiber diameter are vital for a range of fields,such as ultra-high sensitivity sensing and high-speed optical ***,the measurement of fiber diameter relies on point measurement schemes such as microscopes,which suffer from a tradeoff between the resolution and field of *** the fiber can irreversibly damage the fiber samples,especially when multi-point measurements are *** overcome these problems,we have explored a novel technique in which the mechanical properties of fibers are reflected by forward stimulated Brillouin scattering(FSBS),from which the diameters can be demodulated via the acoustic dispersion *** distributed FSBS spectra with narrow linewidths were recorded via the optimized optomechanical time-domain analysis system using coherent FSBS,thereby achieving a spatial resolution of 1 m over a fiber length of tens of *** successfully obtained the diameter distribution of unjacketed test fibers with diameters of 125μm and 80μ*** diameter accuracy was verified by high-quality scanning electron microscope *** achieved a diameter resolution of 3.9 nm,virtually independent of the diameter *** the best of our knowledge,this is the first demonstration of non-destructive and distributed fiber diameter monitoring with nanometer resolution.

关键词： fiber scattering resolution

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长距离分布式布里渊光纤传感关键技术进展分析

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光电工程 2018年第9期45卷 52-61页

作者：王本章逄超周登望董永康哈尔滨工业大学可调谐激光技术国家级重点实验室黑龙江哈尔滨150001

布里渊光纤传感通过光纤中受激布里渊散射效应实现温度和应变测量,具有空间分辨率高、传感距离长和测量精度高等特点,因此分布式布里渊光纤传感成为近年的研究热点。本文通过对长距离分布式布里渊光纤传感研究进展的调研和分析,概括了... 详细信息

布里渊光纤传感通过光纤中受激布里渊散射效应实现温度和应变测量,具有空间分辨率高、传感距离长和测量精度高等特点,因此分布式布里渊光纤传感成为近年的研究热点。本文通过对长距离分布式布里渊光纤传感研究进展的调研和分析,概括了长距离布里渊传感面临的主要限制因素和解决的关键技术,重点介绍了基于时分复用、频分复用、脉冲编码、宽带频率调制和图像处理算法的长距离布里渊光纤传感技术。随着长距离布里渊光纤传感器的实际工程化,对于快速测量的需求愈发显著,这将是未来长距离布里渊光纤传感的主要研究方向。

关键词：受激布里渊散射布里渊光时域分析光纤传感非线性光学

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我国公共图书馆创客空间服务的现状及对策研究

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创新与创业教育 2024年第3期15卷 117-126页

作者：刘娟娟姚登旺浙江旅游职业学院图书馆浙江杭州311231 南京城市职业学院质量管理与科研处江苏南京211200

采用文献研究、网络调查、问卷调查及实地调查法,从图书馆创客空间基础情况、创客空间馆员和创客三个方面对我国公共图书馆创客空间服务现状进行了调查研究,针对调查研究发现的图书馆创客空间存在的定位不明确、服务对象及范围有限、创... 详细信息

采用文献研究、网络调查、问卷调查及实地调查法,从图书馆创客空间基础情况、创客空间馆员和创客三个方面对我国公共图书馆创客空间服务现状进行了调查研究,针对调查研究发现的图书馆创客空间存在的定位不明确、服务对象及范围有限、创客馆员专业能力有待提高、举办活动频率低等问题,提出了明确空间定位、强化服务特色、拓宽服务对象、加强对创客馆员培训及丰富活动内容等相关对策建议。

关键词：公共图书馆创客空间创客服务

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