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Plasmonic tweezers: for nanoscale optical trapping and beyond

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Light(Science & Applications) 2021年第4期10卷 475-515页

作者： Yuquan Zhang Changjun Min Xiujie Dou Xianyou Wang Hendrik Paul Urbach Michael G.Somekh Xiaocong Yuan Nanophotonics research Center Shenzhen Key Laboratory of Micro-Scale Optical Information Technology&Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China optics research group Delft University of TechnologyLorentzweg 12628G DelftThe Netherlands

Optical tweezers and associated manipulation tools in the far field have had a major impact on scientific and engineering research by offering precise manipulation of small *** recently,the possibility of performing manipulation with surface plasmons has opened opportunities not feasible with conventional far-field optical *** use of surface plasmon techniques enables excitation of hotspots much smaller than the free-space wavelength;with this confinement,the plasmonic field facilitates trapping of various nanostructures and materials with higher *** successful manipulation of small particles has fostered numerous and expanding *** this paper,we review the principles of and developments in plasmonic tweezers techniques,including both nanostructure-assisted platforms and structureless *** methods and evaluation criteria of the techniques are presented,aiming to provide a guide for the design and optimization of the *** most common novel applications of plasmonic tweezers,namely,sorting and transport,sensing and imaging,and especially those in a biological context,are critically ***,we consider the future of the development and new potential applications of this technique and discuss prospects for its impact on science.

关键词： trapping offering optical

Towards quantum entanglement of micromirrors via a two-level atom and radiation pressure

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Frontiers of physics 2018年第5期13卷 259-269页

作者： Zhi-Rong Zhong Xin Wang Wei Qin Fujian Key Laboratory of Quantum Information and Quantum optics College of Physics and Information Engineering Fuzhou University Fuzhou 350116 China Institute of Quantum optics and Quantum Information School of Science Xi'an Jiaotong University Xi'an 710049 China Quantum Physics and Quantum Information Division Beijing Computational Science Research Center Beijing 100193 China

We propose a method to entangle two vibrating microsize mirrors （i.e., mechanical oscillators） in a cavity optomechanieal system. In this scheme, we discuss both the resonant and large-detuning conditions, and show that the entanglement of two mechanical oscillators can be achieved with the assistance of a two-level atom and cavity-radiation pressure. In the resonant case, the operation time is relatively short, which is desirable to minimize the effects of decoherence. While in the large-detuning case, the cavity is only virtually excited during the interaction. Therefore, the decay of the cavity is effectively suppressed, which makes the efficient decoherence time of the cavity to be greatly prolonged. Thus, we observe that this virtual-photon process of microscopic objects may induce the entanglement of macroscopic objects. Moreover, in both cases, the generation of entanglement is deterministic and no measurements on the atom and the cavity are required. These are experimentally important. Finally, the decoherence effect and the experimental feasibility of the proposal are briefly discussed.

关键词： cavity optomechanical system atomic entanglement

Mechanics of granular column collapse in fluid at varying slope angles

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Journal of Hydrodynamics 2017年第4期29卷 529-541页

作者： K.Kumar J.-Y.Delenne K.Soga computational Geomechanics research group Department of Engineering University of Cambridge IATE UMR 1208 INRA-CIRAD-Montpellier Supagro-UM2 University of Montpellier 2 Department of Civil and Environmental Engineering University of California

This paper investigates the effect of initial volume fraction on the runout characteristics of collapse of granular columns on slopes in fluid. 2-D sub-grain scale numerical simulations are performed to understand the flow dynamics of granular collapse in fluid. The discrete element method（DEM） technique is coupled with the lattice Boltzmann method（LBM）, for fluid-grain interactions, to understand the evolution of submerged granular flows. The fluid phase is simulated using multiple-relaxation-time LBM（LBM-MRT） for numerical stability. In order to simulate interconnected pore space in 2-D, a reduction in the radius of the grains（hydrodynamic radius） is assumed during LBM computations. The collapse of granular column in fluid is compared with the dry cases to understand the effect of fluid on the runout behaviour. A parametric analysis is performed to assess the influence of the granular characteristics（initial packing） on the evolution of flow and run-out distances for slope angles of 0 °, 2.5°, 5 ° and 7.5 °. The granular flow dynamics is investigated by analysing the effect of hydroplaning, water entrainment and viscous drag on the granular mass. The mechanism of energy dissipation, shape of the flow front, water entrainment and evolution of packing density is used to explain the difference in the flow characteristics of loose and dense granular column collapse in fluid.

关键词： Lattice Boltzmann method(LBM) discrete element method(DEM) granular column collapse granular flows hydroplaning water entrainment viscous drag

Hyperbolic metamaterial using chiral molecules

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Science China(Physics,Mechanics & Astronomy) 2020年第6期63卷 13-21页

作者： JieXing Zhao JingJing Cheng YingQi Chu YanXiang Wang FuGuo Deng Qing Ai Department of Physics Applied Optics Beijing Area Major LaboratoryBeijing Normal UniversityBeijing 100875China NAAM-research group Department of MathematicsFaculty of ScienceKing Abdulaziz UniversityJeddah 21589Saudi Arabia

We theoretically investigate the intra-band transitions in Mobius *** to the weak magnetic response,the relative permittivity is significantly modified by the presence of the medium while the relative permeability is *** show that there is hyperbolic dispersion relation induced by the intra-band transitions because one of the eigen-values of permittivity possesses a different sign from the other two,while all three eigen-values of permeability are *** further demonstrate that the bandwidth of negative refraction is 0.165 eV for the H-polarized incident light,which is broader than the ones for inter-band transitions by 3 orders of ***,the frequency domain has been shifted from ultra-violet to visible *** there is negative refraction for the E-polarized incident light,the bandwidth is much narrower and depends on the incident angle.

关键词： negative refraction hyperbolic dispersion Mobius molecules visible light broad bandwidth

Simultaneous electromagnetically induced transparency and absorption in thermal atomic medium

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Chinese optics Letters 2017年第9期15卷 41-45页

作者： Shangqing Liang Yunfei Xu Qiang Lin Institute of optics Department of Physics Zhejiang University Hangzhou 310027 China Center for optics ＆ Optoelectronics research College of Science Zhejiang University of Technology Hangzhou 310023 China

A three-level lambda system driven by multicolor control, pump, and probe fields is investigated. The pump and probe fields are derived from the same laser with opposite propagating directions. Due to the Doppler effect, the zero group-velocity atoms face bichromatic fields, while other atoms face trichromatic fields. The atomic medium shows distinct characteristics and exhibits simultaneous electromagnetically induced transparency（EIT） and electromagnetically induced absorption（EIA） at two frequencies. EIT and EIA peaks have a fixed relationship with frequency, which is determined by the Doppler shifts.

关键词： EIT EIA Simultaneous electromagnetically induced transparency and absorption in thermal atomic medium

General way to define tunneling time

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Chinese Physics B 2019年第5期28卷 27-31页

作者： Zheng Shu Xiaolei Hao Weidong Li Jing Chen Institute of Applied Physics and computational Mathematics Institute of Theoretical Physics and Department of Physics State Key Laboratory of Quantum Optics and Quantum Optics DevicesCollaborative Innovation Center of Extreme Optics Shanxi University High Energy Density Physics Simulation (HEDPS) Center for Applied Physics and Technology Peking University Center for Advanced Material Diagnostic Technology Shenzhen Technology University

With the development of attosecond science, tunneling time can now be measured experimentally with the attoclock technique. However, there are many different theoretical definitions of tunneling time and no consensus has been ***, we bridge the relationship between different definitions of tunneling time based on a quantum travel time in onedimensional rectangular barrier tunneling problem. We find that the real quantum travel time t_(Re) is equal to the Bohmian time t_(Bohmian), which is related to the resonance lifetime of a bound state. The total quantum travel time τt can perfectly retrieve the transversal time t_x and the Büttiker–Landauer time τ_(BL) in two opposite limits, regardless of the particle energy.

关键词： tunneling time Büttiker–Landauer time Bohmian time

Few-layer MoS2 saturable absorbers for short-pulse laser technology: current status and future perspectives [Invited]

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Photonics research 2015年第2期3卷 30-42页

作者： R.I.Woodward R.C.T.Howe G.Hu F.Torrisi M.Zhang T.Hasan E.J.R.Kelleher Femtosecond optics group Department of Physics Imperial College London Cambridge Graphene Centre University of Cambridge

Few-layer molybdenum disulfide（MoS2） is emerging as a promising quasi-two-dimensional material for photonics and optoelectronics, further extending the library of suitable layered nanomaterials with exceptional optical properties for use in saturable absorber devices that enable short-pulse generation in laser systems. In this work, we catalog and review the nonlinear optical properties of few-layer MoS2, summarize recent progress in processing and integration into saturable absorber devices, and comment on the current status and future perspectives of MoS2-based pulsed lasers.

关键词： Mo current status and future perspectives Invited Few-layer MoS2 saturable absorbers for short-pulse laser technology

Heat Conductivity of One-Dimensional Carbon Chain in an External Potential

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Chinese Physics Letters 2007年第9期24卷 2609-2612页

作者：葛勇董锦明 group of computational Condensed Matter Physics National Laboratory of Solid State Microstructures and Department of Physics Nanjing University Nanjing 210093

The heat transport m a one-dimensional （ID） carbon nanowire （CNW） lying in an external potential with different amplitudes and periods is studied by the non-equilibrium molecular dynamics method. It is found that the thermal conductivity of CNW is always anomalous, increasing with the CNW length and obeying the power law k- N, in which a decreases with the increasing external potential amplitude. The thermal conductivity could be enhanced by the external potential with rather larger amplitudes, which means that an applied external potential could be an efficient tool to improve the heat conductivity of a real 1D material In addition, the effect of different periods of the external potential is studied, finding the external potential with an incommensurate period leads to the smaller a value.

关键词： coated conductor buffer layer self-epitaxy CeO2

Characterization of high nonlinearity in Brillouin amplification in optical fibers with applications in fiber sensing and photonic logic

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Photonics research 2014年第1期2卷 1-9页

作者： Daisy Williams Xiaoyi Bao Liang Chen Fiber optics group University of OttawaOttawaOntario K1N 6N5Canada

A highly accurate,fully analytic solution for the continuous wave and the probe wave in Brillouin amplification,in lossless optical fibers,is *** is experimentally confirmed that the reported analytic solution can account for spectral distortion and pump depletion in the parameter space that is relevant to Brillouin fiber sensor applications,as well as applications in photonic *** analytic solutions are valid characterizations of Brillouin amplification in both the low and high nonlinearity regime,for short fiber lengths.

关键词： fiber optical pump