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Single-row laser beam with energy strengthened ends for continuous scanning laser surface hardening of large metal components

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Science China(Physics,Mechanics & Astronomy) 2013年第6期56卷 1074-1078页

作者： LI ShaoXia YU Gang ZHANG JingChuan tan qiaofeng XU NingHan SUN PeiPei ZHENG CaiYun State Key Laboratory of Precision Measurement Technology and Instruments Tsinghua University Key Laboratory of Mechanics in Advanced Manufacturing Institute of MechanicsChinese Academy of Sciences Beijing Institute of Spacecraft Environment Engineering

For laser surface hardening of metal components with large superficies,a binary grating is proposed to generate single-row laser beam with proportional-intensity diffractive *** obtain a uniform hardened band distribution and improve the wear resistance of the sample surface,the binary grating is designed to produce single-row laser beam with energy strengthened at the two *** profile of the laser beam spot was designed to be strip with high length-width ratio to improve the machining efficiency of the hardening of large surfaces.A new advantage is suggested to obtain proportional intensity spots with *** design results show that the diffractive efficiency of the binary grating is more than 70%,and the uniformity is less than 3%.The surface profile of the grating fabricated was measured,which shows that the fabrication error is less than 2%.The application of the binary grating in the laser surface hardening of metal components with large superficies is experimentally investigated,and the results show that the hardness distribution of the modified layer is more uniform than that hardened by Gaussian laser beam or array spots with equal intensity distribution.

关键词： binary grating beam shaping laser surface hardening diffraction

Helicity dependent directional surface plasmon polariton excitation using a metasurface with interfacial phase discontinuity

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Light(Science & Applications) 2013年第1期2卷 197-203页

作者： Lingling Huang Xianzhong Chen Benfeng Bai qiaofeng tan Guofan Jin Thomas Zentgraf Shuang Zhang School of Physics&Astronomy University of BirminghamBirmingham B152TTUK State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentsTsinghua UniversityBeijing 100084China Department of Physics University of PaderbornD-33098 PaderbornGermany

Surface plasmon polaritons(SPPs)have been widely exploited in various scientific communities,ranging from physics,chemistry to biology,due to the strong confinement of light to the metal *** many applications,it is important that the free space photon can be coupled to SPPs in a controllable *** this Letter,we apply the concept of interfacial phase discontinuity for circularly polarizations on a metasurface to the design of a novel type of polarization-dependent SPP unidirectional excitation at normal *** unidirectional excitation of SPPs along opposite directions is experimentally demonstrated at optical frequencies by simply switching the helicity of the incident *** approach,in conjunction with dynamic polarization modulation techniques,opens gateway towards integrated plasmonic circuits with electrically reconfigurable functionalities.

关键词： metamaterials metasurface surface plasmon

Miniaturized structured illumination microscopy with diffractive optics

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Photonics Research 2022年第5期10卷 1317-1324页

作者： GUOXUAN LIU NING XU HUAIDONG YANG qiaofeng tan GUOFAN JIN State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China

Structured illumination microscopy(SIM)is an advanced microscope system that provides superresolution capability with excellent imaging speed,which has become a practical tool for live-cell ***,the bulky size is blocking the application of SIM in wider study fields and ***,we developed a miniaturized SIM(Mini SIM)system that provided periodic illumination using a diffractive optical element(DOE)for the first *** optimized phase-only DOE generated the two-dimensional sinusoidal illumination by optical Fourier transform with an illuminating objective lens,which substantially simplified and miniaturized the illumination *** built up a Mini SIM prototype and demonstrated lateral superresolution imaging of fluorescence beads and A549 cell *** proposed Mini SIM greatly simplifies the experimental setup and may lead to important applications in bio-imaging.

关键词： illumination optics system

Active coherent control of nanoscale light confinement：Modulation of plasmonic modes and position of hotspots for surface-enhanced Raman scattering detection

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Nano Research 2017年第9期10卷 2934-2943页

作者： Zhendong Zhu Qixia Wang Fa Zeng Oubo You Sitian Gao Benfeng Bai qiaofeng tan Guofan Jin Qunqing Li Shoushan Fan Wei Li Yushu Shi Xueshen Wang Division ofNano Metrology and Materials Measurement National Institute ofMetrology Beijing 100028 China State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision Instrument Tsinghua University Beijing 100084 China Tsinghua-Foxconn Nanotechnology Research Center Tsinghua University Beijing 100084 China Laser Fusion Research Center China Academic of Engineering Physics Mianyang 621900 China

Multistep plasmonic nanostructures can induce the deep modulation of electromagnetic-field interactions on the nanoscale for positioning hotspots, and this generation of enhanced fields is important in many optical applications. In this article, a new strategy is proposed for fabricating a plasmonic doublestacked nanocone (DSC) nanostructure. In the DSC structure, a tunable plasmonic hybrid mode proceeds from the strong coupling of the plasmonic resonance of a fundamental cavity mode with a localized surface plasmon gap mode. In the nanostructure, the far-field response is deeply modulated and the hottest spots can be effectively positioned on the top surface of the DSC nanostructure. A controllable and cost-effective mask-reconfiguration technique for manufacturing the multiscale nanostructure is developed, which guarantees the generation of the introduced crucial stage on the DSC nanostructure. To evaluate the features of the plasmonic resonance, the DSC nanostructure is used as a surface-enhanced Raman scattering (SERS) substrate for detecting 4-mercaptopyridine molecules under specific excitation conditions. Its good performance, with an average measured SERS enhancement factor as high as 108, demonstrates its strong plasmonic-mode hybridization and extreme field enhancement.

关键词： surface plasmons mode hybridization positioning hotspot double-stacked nanocone (DSC) nanostructure surface-enhanced Raman scattering (SERS)

The synthesis of fluorescent nanoclusters based on the etching reaction

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Nano Research 2024年第5期17卷 4631-4638页

作者： Hongbin Lin Yitao Cao qiaofeng Yao Tiankai Chen Huiting Shan Jianping Xie Joint School of National University of Singapore and Tianjin University International Campus of Tianjin UniversityFuzhou 350207China Department of Chemical and Biomolecular Engineering National University of SingaporeSingapore 117585Singapore National and Local Joint Engineering Research Center of MPTES in High Energy and Safety LIBs Engineering Research Center of MTEES(Ministry of Education)and Key Laboratory of ETESPG(GHEI)South China Normal UniversityGuangzhou 510006China Tianjin Key Laboratory of Molecular Optoelectronic Sciences Key Laboratory of Integrated Organic CircuitsMinistry of EducationDepartment of ChemistrySchool of ScienceTianjin UniversityTianjin 300072China

Thiolate-protected atomically precise nanoclusters(NCs)demonstrate a series of unique luminescent characteristics attributed to their various peculiar electronic ***,fluorescent NCs present extraordinary practical values in biosensing and bioimaging research ***,restricted by the types of fluorescent NCs,there are great difficulties in promoting the development of NCs in fluorescent research *** a result,it is of significant necessity for researchers to develop new synthetic pathways to produce high-quality fluorescent *** to the analysis about the structural characteristics of fluorescent NCs,some general features like longer motif and higher ligand-to-metal ratio can be found,consistent to some presented regularities in etching ***,in this work,we used Au_(25)(MHA)_(18)(MHA=6-mercaptohexanoic acid)as a model nanocluster and utilized the etching reaction to systematically explore etching products and their corresponding luminescent ***,we also identified three main reaction processes in the entire etching reaction process,which can generate new metal nanocluster species with various fluorescent ***,the etching reaction will provide a good platform to produce new luminescent metal NC species.

关键词： etching reaction metal nanoclusters fluorescent properties fluorescent conversion

光谱色散匀滑技术与衍射光学器件联用性能的空间频谱分析

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光子学报 2006年第9期35卷 1384-1387页

作者：谭峭峰严瑛白金国藩清华大学精密仪器系精密测试技术与仪器国家重点实验室北京100084

基于空间频谱分析方法,建立了光谱色散匀滑技术(SSD:SmoothingbySpectralDispersion)与衍射光学器件(DOE:DiffractiveOpticalElement)联用性能的简化分析模型,为SSD与DOE联用时,SSD参量的优化提供了理论依据.数值模拟了SSD各参量,包括... 详细信息

基于空间频谱分析方法,建立了光谱色散匀滑技术(SSD:SmoothingbySpectralDispersion)与衍射光学器件(DOE:DiffractiveOpticalElement)联用性能的简化分析模型,为SSD与DOE联用时,SSD参量的优化提供了理论依据.数值模拟了SSD各参量,包括脉冲时间、调制频率、位相调制系数、光栅线色散系数等对束匀滑性能的影响.模拟结果表明,SSD参量经过优化选取,且波前畸变随时间快速变化时,能获得良好的束匀滑性能.

关键词：衍射光学器件束匀滑光谱色散平滑空间频谱

考虑梯级水库库容补偿和设计洪水不确定性的汛限水位动态控制域研究

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工程科学与技术 2017年第1期49卷 60-69页

作者：谭乔凤雷晓辉王浩王旭四川大学水利水电学院四川成都610065 中国水利水电科学研究院北京100038

汛限水位动态控制本质上是风险调度的范畴,其最主要的风险源来自于入库洪水的不确定性。不仅包括由于预报误差带来的实时调度风险,还包括由于设计阶段对于设计洪水不确定性考虑不周而存在的潜在防洪风险。本文针对梯级水库,提出了一种... 详细信息

汛限水位动态控制本质上是风险调度的范畴,其最主要的风险源来自于入库洪水的不确定性。不仅包括由于预报误差带来的实时调度风险,还包括由于设计阶段对于设计洪水不确定性考虑不周而存在的潜在防洪风险。本文针对梯级水库,提出了一种考虑库容补偿和设计洪水不确性的汛限水位动态控制域求解新方法。通过分析梯级水库库容补偿调度原理,定义了水库极限汛限水位上限值,并给出了考虑设计洪水不确定性的防洪风险定量表达式。以Copula函数为工具建立上游和区间天然来水的联合概率密度函数,求出下游遭遇某一设计洪水时,上游可能出现的洪水范围,从而得到考虑梯级水库调蓄作用的不确定性设计洪水。通过反复迭代计算最终得到兼顾防洪风险与兴利效益的汛限水位动态控制域。将该方法运用在考虑潘口库容补偿作用的黄龙滩汛限水位动态控制域计算中,并与同频率法和典型年法比较,得到以下结论:1)所提方法能通过挖掘历史洪水信息,为模拟梯级水库设计洪水不确定性提供参考信息;2)相对于同频率法和典型年法,所提方法推求的汛限水位动态控制域更加的安全;3)黄龙滩水库汛期运行水位可以从[240,247]m变为[240,248.21]m。可使汛期来水较多的2000年和来水较少的1994年分别增加发电量0.13和0.11×108k W·h。所提方法能充分考虑梯级水库库容补偿和设计洪水的不确定性,能得到不增加防洪风险的水库汛限水位动态控制域。

关键词：汛限水位动态控制域库容补偿不确定性风险

Gradient-induced long-range optical pulling force based on photonic band gap

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Light(Science & Applications) 2024年第5期13卷 865-874页

作者： Wenlong Lu Alexey V.Krasavin Sheng Lan Anatoly V.Zayats qiaofeng Dai Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and DevicesSchool of Information and Optoelectronic Science and EngineeringSouth China Normal UniversityGuangzhou 510006China Department of Physics and London Centre for Nanotechnology King’s College LondonLondon WC2R 2LSUK

Optical pulling provides a new degree of freedom in optical *** is generally believed that long-range optical pulling forces cannot be generated by the gradient of the incident ***,we theoretically propose and numerically demonstrate the realization of a long-range optical pulling force stemming from a self-induced gradient field in the manipulated *** analogy to potential barriers in quantum tunnelling,we use a photonic band gap design in order to obtain the intensity gradients inside a manipulated object placed in a photonic crystal waveguide,thereby achieving a pulling *** the usual scattering-type optical pulling forces,the proposed gradient-field approach does not require precise elimination of the reflection from the manipulated *** particular,the Einstein-Laub formalism is applied to design this unconventional gradient *** magnitude of the force can be enhanced by a factor of up to 50 at the optical resonance of the manipulated object in the waveguide,making it insensitive to *** developed approach helps to break the limitation of scattering forces to obtain longrange optical pulling for manipulation and sorting of nanoparticles and other *** developed principle of using the band gap to obtain a pulling force may also be applied to other types of waves,such as acoustic or water waves,which are important for numerous applications.

关键词： optical waveguide scattering

Diffractive optical elements 75 years on:from micro-optics to metasurfaces

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Photonics Insights 2023年第4期2卷 43-101页

作者： Qiang Zhang Zehao He Zhenwei Xie qiaofeng tan Yunlong Sheng Guofan Jin Liangcai Cao Xiaocong Yuan Nanophotonics Research Center Institute of Microscale Optoelectronics&State Key Laboratory of Radio Frequency Heterogeneous IntegrationShenzhen UniversityShenzhenChina Department of Precision Instruments Tsinghua UniversityBeijingChina Center for Optics Photonics and LasersLaval UniversityQuebecCanada Research Institute of Intelligent Sensing Research Center for Humanoid SensingZhejiang LabHangzhouChina

Diffractive optical elements(DOEs)are intricately designed devices with the purpose of manipulating light fields by precisely modifying their *** concept of DOEs has its origins dating back to 1948 when *** first introduced ***,researchers introduced binary optical elements(BOEs),including computer-generated holograms(CGHs),as a distinct category within the realm of *** was the first revolution in optical *** next major breakthrough in light field manipulation occurred during the early 21st century,marked by the advent of metamaterials and *** are particularly appealing due to their ultra-thin,ultra-compact properties and their capacity to exert precise control over virtually every aspect of light fields,including amplitude,phase,polarization,wavelength/frequency,angular momentum,*** advancement of light field manipulation with micro/nano-structures has also enabled various applications in fields such as information acquisition,transmission,storage,processing,and *** this review,we cover the fundamental science,cutting-edge technologies,and wide-ranging applications associated with micro/nano-scale optical devices for regulating light *** also delve into the prevailing challenges in the pursuit of developing viable technology for real-world ***,we offer insights into potential future research trends and directions within the realm of light field manipulation.

关键词： diffractive optical elements metasurfaces metamaterials