检索结果-南通市图书馆

Movement of a millimeter-sized oil drop pushed by optical force

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第10期24卷 223-226页

作者：张莉佘卫龙 State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-Sen University

We show experimentally that when an unfocused continuous wave（CW） laser beam is obliquely incident onto the surface of a millimeter-sized mineral oil drop on sucrose solution, it will exert a pushing force on the oil drop, making it move forwards along the surface of the sucrose solution. However, after a period of time, the oil drop stops moving. This can be explained as the phenomenon caused by the change of Abraham momentum, the optical gradient force, and friction together.

关键词： optical force optical manipulation the movement of a millimeter-sized oil drop

Nonlinear optical trapping effect with reverse saturable absorption

在线全文

学校读者我要写书评

暂无评论

Advanced Photonics 2023年第4期5卷 66-73页

作者： Zheng Zhu Yuquan Zhang Shuoshuo Zhang Aurele J.L.Adam Changjun Min Hendrik Paul Urbach Xiaocong Yuan Shenzhen University Institute of Microscale Optoelectronics and State Key Laboratory of Radio Frequency Heterogeneous IntegrationNanophotonics Research CenterShenzhenChina Research Institute of Intelligent Sensing Research Center for Humanoid SensingZhejiang LabHangzhouChina Delft University of Technology Optics Research GroupDelftThe Netherlands

Nonlinear responses of nanoparticles induce enlightening phenomena in optical tweezers. With thegradual increase in optical intensity, effects from saturable absorption (SA) and reverse SA (RSA) arise insequence and thereby modulate the nonlinear properties of materials. In current nonlinear optical traps,however, the underlying physical mechanism is mainly confined within the SA regime because thresholdvalues required to excite the RSA regime are extremely high. Herein, we demonstrate, both in theory andexperiment, nonlinear optical tweezing within the RSA regime, proving that a fascinating composite trappingstate is achievable at ultrahigh intensities through an optical force reversal induced through nonlinearabsorption. Integrated results help in perfecting the nonlinear optical trapping system, thereby providingbeneficial guidance for wider applications of nonlinear optics.

关键词： nonlinear optical tweezers optical force reverse saturable absorption

On chip chiral and plasmonic hybrid dimer or tetramer:Generic way to reverse longitudinal and lateral optical binding forces

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2022年第5期31卷 305-316页

作者： Sudipta Biswas Roksana Khanam Rumi Tasnia Rahman Raima Saikat Chandra Das M R C Mahdy Department of Electrical&Computer Engineering North South UniversityBashundharaDhaka1229Bangladesh

For both the longitudinal binding force and the lateral binding force,a generic way of controlling the mutual attraction and repulsion(usually referred to as reversal of optical binding force)between chiral and plasmonic hybrid dimers or tetramers has not been reported so far.In this paper,by using a simple plane wave and an onchip configuration,we propose a possible generic way to control the binding force for such hybrid objects in both the near-field region and the far-field region.We also investigate different inter-particle distances while varying the wavelengths of light for each inter-particle distance throughout the investigations.First of all,for the case of longitudinal binding force,we find that chiral-plasmonic hybrid dimer pairs do not exhibit any reversal of optical binding force in the near-field region nor in the far-field region when the wavelength of light is varied in an air medium.However,when the same hybrid system of nanoparticles is placed over a plasmonic substrate,a possible chip,it is possible to achieve a reversal of the longitudinal optical binding force.Later,for the case of lateral optical binding force,we investigate a setup where we place the chiral and plasmonic tetramers on a plasmonic substrate by using two chiral nanoparticles and two plasmonic nanoparticles,with the setup illuminated by a circularly polarized plane wave.By applying the left-handed and the right-handed circular polarization state of light,we also observe the near-field and the far-field reversal of lateral optical binding force for both cases.As far as we know,so far,no work has been reported in the literature on the generic way of reversing the longitudinal optical binding force and the lateral optical binding force of such hybrid objects.Such a generic way of controlling optical binding forces can have important applications in different fields of science and technology in the near future.

关键词： longitudinal binding force plasmonics chirality optical force

Repulsion of polarised particles from anisotropic materials with a near-zero permittivity component

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2016年第1期5卷 752-759页

作者： Francisco J Rodríguez-Fortuño Anatoly V Zayats Department of Physics King’s College LondonStrandLondon WC2R 2LSUK

Reduction of adhesion and stiction is crucial for robust operation on nanomechanical and optofluidic devices as well as atom and molecule behaviour near surfaces.It can be achieved using electric charging,magnetic materials or light pressure and optical trapping.Here we show that a particle scattering or emitting in close proximity to an anisotropic substrate can experience a repulsive force if one of the diagonal components of the permittivity tensor is close to zero.We derive an analytic condition for the existence of such repulsive force depending on the optical properties of the substrate.We also demonstrate the effect using realistic anisotropic metamaterial implementations of a substrate.The anisotropic metamaterial approach using metal–dielectric and graphene–dielectric multilayers provides a tuneable spectral range and a very broad bandwidth of electromagnetic repulsion forces,in contrast to isotropic substrates.

关键词： anisotropy metamaterials optical force repulsion

A DIAGONAL SPLIT-CELL MODEL FOR THE OVERLAPPING YEE FDTD METHOD

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2009年第6期29卷 1670-1676页

作者： Jinjie Liu Moysey Brio Jerome V. Moloney Department of Mathematical Sciences Delaware State University Dover DE 19901 USA Arizona Center for Mathematical Sciences Department of Mathematics University of Arizona Tucson AZ 85721 USA

In this paper, we present a nonorthogonal overlapping Yee method for solv- ing Maxwell＇s equations using the diagonal split-cell model. When material interface is presented, the diagonal split-cell model does not require permittivity averaging so that better accuracy can be achieved. Our numerical results on optical force computation show that the standard FDTD method converges linearly, while the proposed method achieves quadratic convergence and better accuracy.

关键词： FDTD method Overlapping Yee method Maxwell＇s equations optical force

optical manipulation from the microscale to the nanoscale: fundamentals, advances and prospects

在线全文

学校读者我要写书评

暂无评论

Light(Science & Applications) 2017年第1期6卷 593-607页

作者： Dongliang Gao Weiqiang Ding Manuel Nieto-Vesperinas Xumin Ding Mahdy Rahman Tianhang Zhang ChweeTeck Lim Cheng-Wei Qiu Department of Electrical and Computer Engineering National University of SingaporeSingapore 117583Singapore College of Physics Optoelectronics and EnergySoochow UniversitySuzhou 215006China Department of Physics Harbin Institute of TechnologyHarbin 150001China Instituto de Ciencia de Materiales de Madrid Consejo Superior de Investigaciones CientíficasCampus de CantoblancoMadrid 28049Spain Department of Electrical and Computer Engineering North South UniversityDhaka 1229Bangladesh NUS Graduate School for Integrative Sciences and Engineering National University of SingaporeSingapore 117456Singapore Department of Mechanical Engineering National University of SingaporeSingapore 117576Singapore SZU-NUS Collaborative Innovation Center for Optoelectronic Science and Technology Shenzhen UniversityShenzhen 518060China

Since the invention of optical tweezers,optical manipulation has advanced significantly in scientific areas such as atomic physics,optics and biological science.Especially in the past decade,numerous optical beams and nanoscale devices have been proposed to mechanically act on nanoparticles in increasingly precise,stable and flexible ways.Both the linear and angular momenta of light can be exploited to produce optical tractor beams,tweezers and optical torque from the microscale to the nanoscale.Research on optical forces helps to reveal the nature of light–matter interactions and to resolve the fundamental aspects,which require an appropriate description of momenta and the forces on objects in matter.In this review,starting from basic theories and computational approaches,we highlight the latest optical trapping configurations and their applications in bioscience,as well as recent advances down to the nanoscale.Finally,we discuss the future prospects of nanomanipulation,which has considerable potential applications in a variety of scientific fields and everyday life.

关键词： biochemical manipulation microscale nanoscale optical force optical tweezer plasmonics

optical manipulation: from fluid to solid domains

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Insights 2023年第2期2卷 32-90页

作者： Qiannan Jia Wei Lyu Wei Yan Weiwei Tang Jinsheng Lu Min Qiu Key Laboratory of 3D Micro/Nano Fabrication and Characterization of Zhejiang Province School of EngineeringWestlake UniversityHangzhouChina Institute of Advanced Technology Westlake Institute for Advanced StudyHangzhouChina College of Physics and Optoelectronic Engineering Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhouChina Harvard John A.Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeUnited States

Light carries energy and momentum,laying the physical foundation of optical manipulation that has facilitated advances in myriad scientific disciplines,ranging from biochemistry and robotics to quantum physics.Utilizing the momentum of light,optical tweezers have exemplified elegant light–matter interactions in which mechanical and optical momenta can be interchanged,whose effects are the most pronounced on micro and nano objects in fluid suspensions.In solid domains,the same momentum transfer becomes futile in the face of dramatically increased adhesion force.Effective implementation of optical manipulation should thereupon switch to the“energy”channel by involving auxiliary physical fields,which also coincides with the irresistible trend of enriching actuation mechanisms beyond sole reliance on light-momentum-based optical force.From this perspective,this review covers the developments of optical manipulation in schemes of both momentum and energy transfer,and we have correspondingly selected representative techniques to present.Theoretical analyses are provided at the beginning of this review followed by experimental embodiments,with special emphasis on the contrast between mechanisms and the practical realization of optical manipulation in fluid and solid domains.

关键词： optical manipulation optical force adhesion force photothermal effects multiphysics

Laser patterning for the study of MSC cardiogenic differentiation at the single-cell level

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Light(Science & Applications) 2013年第1期2卷 154-162页

作者： Zhen Ma Qiuying Liu Huaxiao Yang Raymond B Runyan Carol A Eisenberg Meifeng Xu Thomas K Borg Roger Markwald Yifei Wang Bruce Z Gao Department of Bioengineering and COMSET Clemson UniversityClemsonSC 29634USA Department of Bioengineering University of CaliforniaBerkeleyBerkeleyCAUSA Biomedical R&D Center Jinan UniversityGuangzhouChina Department of Cellular and Molecular Medicine University of ArizonaTucsonAZ 85724USA New York Medical College/Westchester Medical Center Stem Cell Laboratory New York Medical CollegeValhallaNew YorkUSA Department of Pathology and Laboratory Medicine University of Cincinnati Medical CenterCincinnatiOHUSA Department of Regenerative Medicine and Cell Biology Medical University of South CarolinaCharlestonSCUSA

Mesenchymal stem cells(MSCs)have been cited as contributors to heart repair through cardiogenic differentiation and multiple cellular interactions,including the paracrine effect,cell fusion,and mechanical and electrical couplings.Due to heart–muscle complexity,progress in the development of knowledge concerning the role of MSCs in cardiac repair is heavily based on MSC–cardiomyocyte coculture.In conventional coculture systems,however,the in vivo cardiac muscle structure,in which rod-shaped cells are connected end-to-end,is not sustained;instead,irregularly shaped cells spread randomly,resulting in randomly distributed cell junctions.Consequently,contact-mediated cell–cell interactions(e.g.,the electrical triggering signal and the mechanical contraction wave that propagate through MSC–cardiomyocyte junctions)occur randomly.Thus,the data generated on the beneficial effects of MSCs may be irrelevant to in vivo biological processes.In this study,we explored whether cardiomyocyte alignment,the most important phenotype,is relevant to stem cell cardiogenic differentiation.Here,we report(i)the construction of a laser-patterned,biochip-based,stem cell–cardiomyocyte coculture model with controlled cell alignment;and(ii)single-cell-level data on stem cell cardiogenic differentiation under in vivo-like cardiomyocyte alignment conditions.

关键词： cardiogenic differentiation mesenchymal stem cells microenvironment optical force single-cell analysis