scholarly journals Microscale solute flow probed with rotating microbead trapped in optical vortex

2021 ◽  
Vol 62 (6) ◽  
Author(s):  
Weronika Lamperska ◽  
Jan Masajada ◽  
Sławomir Drobczyński
Keyword(s):  
Optical Tweezers ◽  
Surrounding Medium ◽  
Solute Concentration ◽  
Optical Vortex ◽  
Solute Flow ◽  
Elementary Problem ◽  
And Diffusion ◽  
Viscosity Changes ◽  
Dark Core ◽  
Measurement Chamber

AbstractThe dynamics of solute flow in the microscopic chamber can be studied with optical tweezers. A method based on the metallic microbeads trapped in the focused optical vortex beam is proposed. This annular beam of a twisted wavefront exerts torque on a reflective object placed inside the dark core of the vortex. The induced rotational movement of the bead is sensitive to local viscosity changes in the surrounding medium, for example, during the ongoing dissolution process. Two experimental configurations are described, both relying on tracing the angular velocity of the bead in time. In one-bead configuration, the dynamics of local solute concentration can be studied. In two-bead case, the direction and speed of solute flow can be probed with a spatial resolution of single micrometers. We approach the elementary problem of sucrose dissolution and diffusion in water. The surprising impression of the reverse solute flow was observed. Further experimental investigation led to the discovery that this phenomenon originates from the sucrose stream-like diffusion in the mid-depth of the measurement chamber. The rotating microbead method applies for various solid and liquid substances and may become a useful technique for microfluidics research. Graphic abstract

scholarly journals Optical vortex lattice: an exploitation of orbital angular momentum

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Liuhao Zhu ◽  
Miaomiao Tang ◽  
Hehe Li ◽  
Yuping Tai ◽  
Xinzhong Li
Keyword(s):  
Angular Momentum ◽  
Optical Tweezers ◽  
Orbital Angular Momentum ◽  
Vortex Lattice ◽  
Optical Vortex ◽  
Yeast Cells ◽  
Particle Manipulation ◽  
Complex Motion ◽  
Potential Applications ◽  
Vortex Beams

Abstract Generally, an optical vortex lattice (OVL) is generated via the superposition of two specific vortex beams. Thus far, OVL has been successfully employed to trap atoms via the dark cores. The topological charge (TC) on each optical vortex (OV) in the lattice is only ±1. Consequently, the orbital angular momentum (OAM) on the lattice is ignored. To expand the potential applications, it is necessary to rediscover and exploit OAM. Here we propose a novel high-order OVL (HO-OVL) that combines the phase multiplication and the arbitrary mode-controllable techniques. TC on each OV in the lattice is up to 51, which generates sufficient OAM to manipulate microparticles. Thereafter, the entire lattice can be modulated to desirable arbitrary modes. Finally, yeast cells are trapped and rotated by the proposed HO-OVL. To the best of our knowledge, this is the first realization of the complex motion of microparticles via OVL. Thus, this work successfully exploits OAM on OVL, thereby revealing potential applications in particle manipulation and optical tweezers.

Aberration correction in holographic optical tweezers using a high-order optical vortex: publisher’s note

2018 ◽  
Vol 57 (17) ◽  
pp. 4857
Author(s):  
Yansheng Liang ◽  
Yanan Cai ◽  
Zhaojun Wang ◽  
Ming Lei ◽  
Zhiliang Cao ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Optical Vortex ◽  
High Order ◽  
Aberration Correction ◽  
Holographic Optical Tweezers

scholarly journals Strongly Focused Circularly Polarized Optical Vortices Regulated by a Fractal Conical Lens

2019 ◽  
Vol 10 (1) ◽  
pp. 28
Author(s):  
Zhirong Liu ◽  
Kelin Huang ◽  
Anlian Yang ◽  
Xun Wang ◽  
Philip H. Jones
Keyword(s):  
Angular Momentum ◽  
Optical Tweezers ◽  
Numerical Aperture ◽  
Optical Element ◽  
Optical Vortex ◽  
Optical Vortices ◽  
Circularly Polarized ◽  
Strong Focusing ◽  
New Type ◽  
Vortex Beams

In this paper, a recently-proposed pure-phase optical element, the fractal conical lens (FCL), is introduced for the regulation of strongly-focused circularly-polarized optical vortices in a high numerical aperture (NA) optical system. Strong focusing characteristics of circularly polarized optical vortices through a high NA system in cases with and without a FCL are investigated comparatively. Moreover, the conversion between spin angular momentum (SAM) and orbital angular momentum (OAM) of the focused optical vortex in the focal vicinity is also analyzed. Results revealed that a FCL of different stage S could significantly regulate the distributions of tight focusing intensity and angular momentum of the circularly polarized optical vortex. The interesting results obtained here may be advantageous when using a FCL to shape vortex beams or utilizing circularly polarized vortex beams to exploit new-type optical tweezers.

Light-Induced Agglomeration and Diffusion of Different Particles with Optical Tweezers

2010 ◽  
Vol 27 (9) ◽  
pp. 098101 ◽  
Author(s):  
Li Xue-Cong ◽  
Sun Xiu-Dong ◽  
Liu Hong-Peng ◽  
Zhang Jian-Long
Keyword(s):  
Optical Tweezers ◽  
And Diffusion

Electromigration and Diffusion in Short Al-Ni-Cr Lines

1998 ◽  
Vol 516 ◽  
Author(s):  
L.C. Jacobs ◽  
A.H. Verbruggen ◽  
A.J. Kalkman ◽  
S. Radelaar
Keyword(s):  
Activation Energy ◽  
Current Density ◽  
Threshold Current ◽  
Solute Concentration ◽  
Threshold Current Density ◽  
Sample Length ◽  
Exponential Factor ◽  
Current Stressing ◽  
Induced Changes ◽  
And Diffusion

AbstractTo investigate why the formation of electromigration damage in Al lines alloyed with both 0.1 at.% Ni and 0.1 at.% Cr is so effectively suppressed we studied electromigration induced changes in the electrical resistance of short lines. The length of the lines is 4, 6, 8, or 12 µm, the width is 4 µm and the film thickness is 0.3 µm. As previously reported for pure Al lines, depending on current density and sample length, the induced resistance changes fully recover or do not recover after DC stressing for a few hours. The recoverable resistance changes correspond to the build-up or relaxation of mechanical stress and the permanent resistance changes to the formation of a void or hillock. Electron microprobe analysis and resistance measurements after prolonged current stressing provided no evidence for changes in local solute concentration. Therefore diffusion of Al along grain boundaries is regarded as the dominating diffusion process. The activation energy and the pre-exponential factor of this process are determined from the temperature dependence of the relaxation time of the recoverable resistance changes. The activation energy of this process is 0.84±0.03 eV and the pre-exponential factor δD0 = (1.8±0.8)×10−8 cm3/s. At 175 °C the resulting diffusion coefficient is about a factor 70 smaller than that of pure Al. The transition from recoverable to permanent resistance changes is characterized by a constant critical current density -sample length product. It is found that the value of this product for the Al-Ni-Cr lines is two times larger than the value found for pure Al lines. This means that the threshold current density at given sample length for the formation of hillocks or voids is two times larger. Both the slower solvent diffusion and the higher threshold current density contribute positively to a long electromigration lifetime.

scholarly journals Aberration correction in holographic optical tweezers using a high-order optical vortex

2018 ◽  
Vol 57 (13) ◽  
pp. 3618 ◽  
Author(s):  
Yansheng Liang ◽  
Yanan Cai ◽  
Zhaojun Wang ◽  
Ming Lei ◽  
Zhiliang Cao ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Optical Vortex ◽  
High Order ◽  
Aberration Correction ◽  
Holographic Optical Tweezers

scholarly journals Experimental demonstration of cylindrical vector spatiotemporal optical vortex

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jian Chen ◽  
Chenhao Wan ◽  
Andy Chong ◽  
Qiwen Zhan
Keyword(s):  
Angular Momentum ◽  
Optical Tweezers ◽  
Orbital Angular Momentum ◽  
Optical Vortex ◽  
Spin Orbit ◽  
Experimental Demonstration ◽  
Matter Interaction ◽  
Light Matter Interaction ◽  
Angular Momentum Coupling ◽  
Momentum Coupling

Abstract We experimentally generate cylindrically polarized wavepackets with transverse orbital angular momentum, demonstrating the coexistence of spatiotemporal optical vortex with spatial polarization singularity. The results in this paper extend the study of spatiotemporal wavepackets to a broader scope, paving the way for its applications in various areas such as light–matter interaction, optical tweezers, spatiotemporal spin–orbit angular momentum coupling, etc.

scholarly journals Trap, ignition, and diffusion combustion characteristics of active carbon micro-particles at a meso-scale studied by optical tweezers

2014 ◽  
Vol 63 (17) ◽  
pp. 178802
Author(s):  
Huang Xue-Feng ◽  
Li Sheng-Ji ◽  
Zhou Dong-Hui ◽  
Zhao Guan-Jun ◽  
Wang Guan-Qing ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Active Carbon ◽  
Combustion Characteristics ◽  
Diffusion Combustion ◽  
Micro Particles ◽  
And Diffusion ◽  
Meso Scale

The Flow and Diffusion of Radon Isotopes in Fractured Porous Media: Part 2, Semi-infinite Media

1988 ◽  
Vol 24 (1-4) ◽  
pp. 191-197 ◽  
Author(s):  
S.D. Schery ◽  
D.J. Holford ◽  
J.L. Wilson ◽  
F.M. Phillips
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Surrounding Medium ◽  
Infinite Medium ◽  
Concentration Characteristic ◽  
Pressure Driven Flow ◽  
And Diffusion ◽  
Infinite Media ◽  
Diffusive Exchange ◽  
Radon Isotopes

Abstract The release of radon isotopes under conditions of combined diffusion and flow from a fractured, semi-infinite medium such as soil is analysed. Relations are developed to indicate when flow from fractures will dominate overall transport and when the radon released from fractures will have the concentration characteristic of great depths. The presence of pressure-driven flow from fractures can greatly enhance transport of radon, but narrow or shallow fractures are not necessarily important due to the strong diffusive exchange with the surrounding porous medium and a reduced vertical pressure gradient in the surrounding medium. Results should be of use in estimating whether fractures are important in transporting radon to air spaces where pollution from radon is a concern.

Grain Boundary Structure and Diffusion Induced Grain Boundary Migration

1991 ◽  
Vol 229 ◽  
Author(s):  
A. H. King
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Migration ◽  
Structural Models ◽  
Solute Concentration ◽  
Boundary Structure ◽  
Grain Boundary Migration ◽  
Grain Boundary Structure ◽  
And Diffusion

AbstractWe present a review of systematic studies of diffusion induced grain boundary migration (DIGM). The results are compared with structural models for the grain boundaries in order to assess the effects of structure upon DIGM. The nucleation of DIGM is also assessed in the light of grain boundary structure and it is demonstrated that changes of grain boundary solute concentration can induce large enough energy changes to drive novel grain boundary dissociation reactions.

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