Optical tweezers : methods and applications
Free download. Book file PDF easily for everyone and every device. You can download and read online Optical tweezers : methods and applications file PDF Book only if you are registered here. And also you can download or read online all Book PDF file that related with Optical tweezers : methods and applications book. Happy reading Optical tweezers : methods and applications Bookeveryone. Download file Free Book PDF Optical tweezers : methods and applications at Complete PDF Library. This Book have some digital formats such us :paperbook, ebook, kindle, epub, fb2 and another formats. Here is The CompletePDF Book Library. It's free to register here to get Book file PDF Optical tweezers : methods and applications Pocket Guide.
Contents:
Light carries momentum that is proportional to its energy and in the direction of propagation. Any change in the direction of light, by reflection or refraction, will result in a change of the momentum of the light.
Summary. The technical development of optical tweezers, along with their application in the biological and physical sciences, has progressed significantly since. Giovanni Volpe. To cite this article: Giovanni Volpe (): Optical Tweezers: Methods and Applications, edited by Miles J. Padgett, Justin. Molloy and David McGloin, Contemporary Physics, ,
If an object bends the light, changing its momentum, conservation of momentum requires that the object must undergo an equal and opposite momentum change. This gives rise to a force acting on the object. In a typical optical tweezers setup the incoming light comes from a laser which has a Gaussian intensity profile. Basically, the light at the center of the beam is brighter than the light at the edges.
Account Options
When this light interacts with a bead, the light rays are bent according the laws of reflection and refraction two example rays are shown above. The sum of the forces from all such rays can be split into two components: the scattering force, pointing in the direction of the incident light , and the gradient force, arising from the gradient of the Gaussian intensity profile and pointing in xy plane towards the center of the beam.
The gradient force is a restoring force that pulls the bead into the center. If the contribution to the scattering force of the refracted rays is larger than that of the reflected rays then a restoring force is also created along the z axis, yielding a stable trap. The image of the bead can be projected onto a quadrant photodiode to measure nm-scale displacements.
When the bead is displaced from the center of the trap, what force does it feel? The restoring force of the optical trap works like an optical spring: the force is proportional to the displacement out of the trap. In practice, the bead is constantly moving with Brownian motion.
But whenever it leaves the center of the optical trap the restoring force pulls it back to the center.
Fluorescence microscopy. Biological systems. Hashemi Shabestari, M. Meijering and W.
Roos and G. Wuite and Erwin Peterman",. AU - Meijering, A.
Dynamic Holographic Optical Tweezers
AU - Roos, W. Topological phases can appear in condensed-matter systems naturally, whereas the implementation and study of such quantum many-body ground states in artificial matter require careful engineering. Here, we report the experimental realization of a symmetry-protected topological phase of interacting bosons in a one-dimensional lattice and demonstrate a robust ground state degeneracy attributed to protected zero-energy edge states. The experimental setup is based on atoms trapped in an array of optical tweezers and excited into Rydberg levels, which gives rise to hard-core bosons with an effective hopping generated by dipolar exchange interaction.
Optical tweezers also support the study of the dynamics of two or multiple interacting particles. Jesacher A. Two of the main uses for optical traps have been the study of molecular motors and the physical properties of DNA. Applications in Microfluidics. This means that particles are propelled by the evanescent field while being trapped by the linear bright fringes.
Journal: Science 0 comments. Thursday, August 22, Aggregation and coalescence of partially crystalline emulsion drops investigated using optical tweezers. Mariela R.
An introduction to optical tweezers
Osborne, Matt Golding and Martin A. Williams The solid content of viscoelastic emulsion drops is known to affect their propensity for aggregation and their subsequent coalescence behaviour, where the balance between the drive to reduce surface tension and the straining of an internal viscoelastic network is able to create a plethora of stable partially-coalesced states. The latter has previously been elegantly demonstrated in synthetic systems, generated using oil containing different phase volumes of added solids, with micro-pipette experiments carried out on emulsion drops of several tens of microns in size.
Herein we carry out experiments in the same spirit but aided by optical tweezers OT and using smaller micron-sized emulsion drops generated from milk fat. Given the size dependence of Brownian fluctuations and Laplace pressure the experimental investigation of these smaller drops is not necessarily a trivial extension of the previous work. The solid content of initially separated drops is controlled using a temperature-cycling regime in the sample preparation protocol, and subsequently the propensity for drops to remain joined or not after being brought into contact was examined.
Aggregated pairs of drops were then subjected to an increase in temperature, either locally using a high-powered laser, or more globally using a custom-made Peltier temperature-controller. By heating to different degrees, the amount of fat crystals in the drops was able to be controlled, with progressively more compact partially-coalesced states, and eventually complete coalescence generated as the solid content was reduced. While in contrast to previous studies, the emulsion studied here was quite different in size and nature, and the solid content was controlled using temperature, the same underlying physics was nevertheless observed.
Journal: Soft Matter 0 comments.
Optical Tweezers & Micromanipulation
Size-scaling effects for microparticles and cells manipulated by optoelectronic tweezers. Clark, Aaron R. Wheeler, and Steven L. Neale In this work, we investigated the use of optoelectronic tweezers OET to manipulate objects that are larger than those commonly positioned with standard optical tweezers. We studied the forces that could be produced on differently sized polystyrene microbeads and MCF-7 breast cancer cells with light-induced dielectrophoresis DEP.
Although this size-scaling work focuses on microparticles and cells, we propose that the physical mechanism elucidated in this research will be insightful for other micro-objects, biological samples, and micro-actuators undergoing OET manipulation. Email This BlogThis! Journal: Optics Letters 0 comments.
- The Darkest Days: The Truth Behind Britains Rush to War, 1914.
- ATEX—Explosive Atmospheres: Risk Assessment, Control and Compliance.
- Navigation menu.
- Exploring the New World: Early America.
- Optical Tweezers;
- Optical Tweezers: Methods and Applications, 1st Edition (Hardback) - Routledge!
Older Posts Home. Subscribe to: Posts Atom.