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*  Blog on Optical Tweezers: March 2012
Single-molecule manipulation instruments, such as optical traps and magnetic tweezers, frequently use video tracking to measure ... the results of calibration are estimates of the probe drag, α, and spring constant, κ. Here, we present both time- and ... Optical Fiber Technology (1) Optical Materials (1) Optical Materials Express (3) Optical Memory and Neural Networks (1) Optical ... Blog on Optical Tweezers Concisely bringing the latest news and relevant information regarding optical trapping and ...
  http://opticaltweezers.blogspot.com/2012_03_01_archive.html
*  Blog on Optical Tweezers: January 2011
We explain the flake dynamics in the optical trap and measure force and torque constants from the correlation functions of the ... In single-molecule mechanical studies using optical or magnetic tweezers, such attachments must be able to withstand the ... the inconsistencies highlighted in recent calibration measurements of critical supersaturations of sodium chloride and ammonium ... Optical Fiber Technology (1) Optical Materials (1) Optical Materials Express (3) Optical Memory and Neural Networks (1) Optical ...
  http://opticaltweezers.blogspot.com/2011_01_01_archive.html
*  Blog on Optical Tweezers: September 2010
We demonstrate the trapping of individual fluorescent beads on the stripe, which supports a single quasi-transverse magnetic ( ... Using the response of our detection system to a single atom as a calibration, we extract the atom number distribution when the ... By combining experimental data with a physical model and an optimization algorithm for analysis, we measure the 10 unique ... Optical Fiber Technology (1) Optical Materials (1) Optical Materials Express (3) Optical Memory and Neural Networks (1) Optical ...
  http://opticaltweezers.blogspot.com/2010_09_01_archive.html
*  Blog on Optical Tweezers: February 2010
A novel "dot" Janus particle is presented, which is compatible with optical traps and magnetic fields, allowing for direct ... We used optical tweezers to measure the rupture force between HU proteins and Lon; HUα, HUβ, and HUβ-A20D can bind to Lon, and ... The obtained results both for trapping calibration beads and for living bacteria show that the proposed approach allows the ... Optical fibre probe-based near-field optical tweezers overcomes the diffraction limit of conventional optical tweezers, ...
  http://opticaltweezers.blogspot.com/2010/02/
*  Using GPUs for Realtime Prediction of Optical Forces on Microsphere Ensembles | Journal of Computing and Information Science in...
Laser beams can be used to create optical traps that can hold and transport small particles. Optical trapping has been used in a number of applications ranging from prototyping at the microscale to biological cell manipulation. Successfully using optical tweezers requires predicting optical forces on the particle being trapped and transported. Reasonably accurate theory and computational models exist for predicting optical forces on a single particle in the close vicinity of a Gaussian laser beam. However, in practice the workspace includes multiple particles that are manipulated using individual optical traps. It has been experimentally shown that the presence of a particle can cast a shadow on a nearby particle and hence affect the ...
  http://computingengineering.asmedigitalcollection.asme.org/article.aspx?articleid=1682058
*  Tweezer/high-powered Tweezer, Tweezer/high-powered Tweezer Suppliers and Manufacturers at Alibaba.com
Tweezer/high-powered Tweezer, Wholesale Various High Quality Tweezer/high-powered Tweezer Products from Global Tweezer/high-powered Tweezer Suppliers and Tweezer/high-powered Tweezer Factory,Importer,Exporter at Alibaba.com.
  http://www.alibaba.com/showroom/tweezer%252fhigh--powered-tweezer.html
*  Optical Tweezers : Optical Tweezers Microscope System
The trapping source for the Optical Tweezers System is a power- and wavelength-stabilized 1064 nm laser, which is split into two independently steerable trapping beams with greater than 1 W optical power per beam. Each beam can support several time-shared traps. Other trapping wavelengths and powers are available for specialized applications.. The output of the trapping laser is collimated, and the light is focused onto the sample with diffraction-limited performance, thereby achieving optical gradients capable of trapping particles. Force measurements in the femtonewton to piconewton range can be performed using the included force measurement module. Quadrant detectors monitor a signal sensitive to the relative displacement of the trapped particle from the laser beam axis. As a result, the output of the detector can be used ...
  http://www.aitc-group.com/alahram2/index.php/products/applications/optical-tweezers/optical-tweezers-microscope-system-detail
*  OSA | Design for fully steerable dual-trap optical tweezers
A design for complete beam steering (in three dimensions) of one or two optical tweezers traps is presented. The two most important requirements for efficient and stable movement of an optical trap are identified. A detailed recipe for the construction of a movable optical tweezers trap that fulfills these requirements is given (exemplified with an inverted microscope). The system has been found to allow for precise and free movements of both traps in all three dimensions in a dual-trap optical tweezers configuration and to be robust and reliable, as well as forgiving of small misalignments in the optical system.. © 1997 Optical Society of America. Full Article , PDF Article ...
  https://www.osapublishing.org/ao/abstract.cfm?uri=ao-36-10-2107
*  Optical tweezers: 20 years on | Philosophical Transactions of the Royal Society of London A: Mathematical, Physical and...
In 1986, Arthur Ashkin and colleagues published a seminal paper in Optics Letters, 'Observation of a single-beam gradient force optical trap for dielectric particles' which outlined a technique for trapping micrometre-sized dielectric particles using a focused laser beam, a technology which is now termed optical tweezers. This paper will provide a background in optical manipulation technologies and an overview of the applications of optical tweezers. It contains some recent work on the optical manipulation of aerosols and concludes with a critical discussion of where the future might lead this maturing technology. ...
  http://rsta.royalsocietypublishing.org/content/364/1849/3521
*  Optical Tweezers Control Free Download
Optical Tweezers Control - Optical trap control software. This project provides an example LabVIEW software program to perform data acquisition and feedback control of optical tweezers, especially for single-molecule biophysics experiments.
  https://optical-tweezers-control.soft112.com/
*  A simple method to fulfill particle trapping by optical tweezers array | (2010) | Hu | Publications | Spie
We adopt double-plate sheering interferometers to perform an optical tweezers array system. In the optical tweezers array system, the reflecting mirror is replaced by an optical scanner to be a beam translator. The optical scanner is driven by an input signal to control the interference strips movement. However, if the interference strips move periodically, the trapped particles would move along with the strips with the same regulation. So, the particles could not be separated from the other particles. We use an external modulating device to be a shutter to control the laser beam. Then the trapped particles would continue moving because of inertia during the laser beam is blocked, and be trapped again after the shutter opens. If the moving speed of liquid is limited properly, the particles can be separated ...
  http://spie.org/Publications/Proceedings/Paper/10.1117/12.870281
*  User:Pranav Rathi/Notebook/OT/2012/11/13/Optical Tweezers Calibration - OpenWetWare
To perform accurate measurements with optical tweezers, it is necessary to calibrate some experimental parameters and even before that study the active components of the optical tweezers setup. The parameters I want to calibrate: Stiffness; which measures the force that is exerts on the trapped bead, and Sensitivity; which measures the relative position of bead within the trap. The components I want to study: Laser, AOM (acoustooptic module), microscope objective, QPD (quadrant photo diode), z and x piezo. It is necessary to characterize these components first because not only they affect the experimental parameters but also reduce the chances to see something unexpected in data later on. ...
  https://openwetware.org/wiki/?title=User:Pranav_Rathi/Notebook/OT/2012/11/13/Optical_Tweezers_Calibration&curid=126877&oldid=657036
*  Difference between revisions of "User:Pranav Rathi/Notebook/OT/2012/11/13/Optical Tweezers Calibration" - OpenWetWare
To perform accurate measurements with optical tweezers, it is necessary to calibrate some experimental parameters and even before that study the active components of the optical tweezers setup. The parameters I want to calibrate: Stiffness; which measures the force that is exerts on the trapped bead, and Sensitivity; which measures the relative position of bead within the trap. The components I want to study: Laser, AOM (acoustooptic module), microscope objective, QPD (quadrant photo diode), z and x piezo. It is necessary to characterize these components first because not only they affect the experimental parameters but also reduce the chances to see something unexpected in data later on. ...
  https://openwetware.org/wiki/?title=User:Pranav_Rathi/Notebook/OT/2012/11/13/Optical_Tweezers_Calibration&diff=next&oldid=655094
*  Difference between revisions of "User:Pranav Rathi/Notebook/OT/2012/11/13/Optical Tweezers Calibration" - OpenWetWare
To perform accurate measurements with optical tweezers, it is necessary to calibrate some experimental parameters and even before that study the active components of the optical tweezers setup. The parameters I want to calibrate: Stiffness; which measures the force that is exerts on the trapped bead, and Sensitivity; which measures the relative position of bead within the trap. The components I want to study: Laser, AOM (acoustooptic module), microscope objective, z and x piezo, lens and mirrors, and QPD (quadrant photo diode). It is necessary to characterize these components first because not only they affect the experimental parameters but also reduce the chances to see something unexpected in data later on. ...
  https://openwetware.org/wiki/?title=User:Pranav_Rathi/Notebook/OT/2012/11/13/Optical_Tweezers_Calibration&diff=next&oldid=657038
*  Fundamental constraints on particle tracking with optical tweezers - UQ eSpace
A general quantum limit to the sensitivity of particle position measurements is derived following the simple principle of the Heisenberg microscope. The value of this limit is calculated for particles in the Rayleigh and Mie scattering regimes, and with parameters which are relevant to optical tweezers experiments. The minimum power required to observe the zero-point motion of a levitating bead is also calculated, with the optimal particle diameter always smaller than the wavelength. We show that recent optical tweezers experiments are within two orders of magnitude of quantum limited sensitivity, suggesting that quantum optical resources may soon play an important role in high sensitivity tracking applications ...
  https://espace.library.uq.edu.au/view/UQ:294075
*  CACHE . An Introduction of Optical Trapping and the Construction of a Dual Beam Optical Tweezers . Kalamazoo College
Optical tweezers give us an unprecedented ability to manipulate objects on the microscopic scale. This ability allows us to study and quantify the mechanics of microscopic objects such as blood cells, DNA, proteins, bacteria, viruses, and sperm. Many ingenious experiments have been performed over the past few years taking advantage of this tool. However, this innovation is still relatively new and many of its future applications are just being discovered. In this paper I describe the basic theory of optical trapping along with the construction, alignment, motorization, and calibration of a dual beam optical tweezers ...
  https://cache.kzoo.edu/handle/10920/23279
*  Techniques for optical tweezers and SLM microscopy - Enlighten: Theses
With the development of pixelated liquid crystal displays, a new paradigm has emerged in the field of optics. Essentially, these displays enable interfacing a computer program with light, and therefore allow a wide range of light beams to be created. In this thesis, I shall be using liquid crystal displays to create phase diffraction patterns and, in this case, the displays are more commonly referred to as Spatial Light Modulators (SLMs). One area where SLMs have shown particular promise is that of optical microscopy. Here, they have been used in two different applications, namely holographic optical tweezers and SLM microscopy; this thesis concerns both. The aim of the thesis is to explore and develop new techniques combining SLMs with microscopy. The first part of this thesis goes into results of the experiments I have carried out in holographic optical ...
  http://theses.gla.ac.uk/5552/
*  Optical Tweezers | Physics Forums - The Fusion of Science and Community
Optical tweezers are simply a technique- there's many published designes out there, so any PI could build one as they see fit. There's research on trapping as well, but I don't think that's really what you mean ...
  https://www.physicsforums.com/threads/optical-tweezers.228393/
*  OSA | Enhanced optical forces between coupled resonant metal nanoparticles
We investigate numerically the optical forces between noble metal nanoparticles sustaining localized surface plasmon resonances. Our results first point out enhanced binding optical forces compared with dielectric nanoparticles and nonresonant metallic nanoparticles. We also show that under suitable illumination conditions, short-range forces tend to make the nanoparticles cluster, leading to intense and localized hot spots in the interstices. This effect corroborates recent experimental observations of an enhanced Raman signal in trapped metal sphere ensembles.. © 2007 Optical Society of America. Full Article , PDF Article ...
  https://www.osapublishing.org/vjbo/abstract.cfm?uri=ol-32-9-1156
*  Holographic optical tweezers combined with back-focal-plane displacement detection
A major problem with holographic optical tweezers (HOTs) is their incompatibility with laser-based position detection methods, such as back-focal-plane interferometry (BFPI). The alternatives generally used with HOTs, like high-speed video tracking, do not offer the same spatial and temporal bandwidths. This has limited the use of this technique in precise quantitative experiments. In this paper, we present an optical trap design that combines digital holography and back-focal-plane displacement detection. We show that, with a particularly simple setup, it is possible to generate a set of multiple holographic traps and an additional static non-holographic trap with orthogonal polarizations and that they can be, therefore, easily separated for measuring positions and forces with the high positional and temporal resolutions of laser-based detection. We prove that measurements ...
  http://www.recercat.cat/handle/2072/227926
*  OSA | Real-time actin-cytoskeleton depolymerization detection in a single cell using optical tweezers
The cytoskeleton provides the backbone structure for the cellular organization, determining, in particular, the cellular mechanical properties. These are important factors in many biological processes, as, for instance, the metastatic process of malignant cells. In this paper, we demonstrate the possibility of monitoring the cytoskeleton structural transformations in optically trapped yeast cells (Saccharomyces cerevisiae) by tracking the forward scattered light via a quadrant photodiode. We distinguished normal cells from cells treated with latrunculin A, a drug which is known to induce the actin-cytoskeleton depolymerization. Since the proposed technique relies only on the inherent properties of the optical trap, without requiring external markers or biochemical sensitive spectroscopic techniques, it can be readily combined with existing optical tweezers setups.. ©2007 ...
  https://www.osapublishing.org/oe/abstract.cfm?URI=oe-15-13-7922
*  OSA | Two-photon fluorescence excitation in continuous-wave infrared optical tweezers
We report the observation of two-photon fluorescence excitation in a continuous-wave (cw) single-beam gradient force optical trap and demonstrate its use as an in situ probe to study the physiological state of an optically confined sample. In particular, a cw Nd:YAG (1064-nm) laser is used simultaneously to confine, and excite visible fluorescence from submicrometer regions of, cell specimens. Two-photon fluorescence emission spectra are presented for motile human sperm cells and immotile Chinese hamster ovary cells that have been labeled with nucleic acid (Propidium Iodide) and pH-sensitive (Snarf) fluorescent probes. The resulting spectra are correlated to light-induced changes in the physiological state experienced by the trapped cells. This spectral technique should prove extremely useful for monitoring cellular activity and the effects of confinement by optical ...
  https://www.osapublishing.org/ol/abstract.cfm?uri=ol-20-21-2246
*  Cancer immunotherapy μ-environment LabChip: taking advantage of optoelectronic tweezers - Lab on a Chip (RSC Publishing)
A cancer immunotherapy μ-environment LabChip, equipped with titanium oxide phthalocyanine (TiOPc)-based optoelectronic tweezers (OET) to achieve direct cell-cell contact, can be used to study the interaction between immune cells and other cells for real-time analysis of NK cells' behavior. In microfluidic devices,
  http://pubs.rsc.org/en/content/articlelanding/2018/lc/c7lc00963a
*  Pakistan Tweezerman Tweezers, Pakistan Tweezerman Tweezers Manufacturers and Suppliers on Alibaba.com
Pakistan Tweezerman Tweezers, Pakistan Tweezerman Tweezers Suppliers and Manufacturers Directory - Source a Large Selection of Tweezerman Tweezers Products at eyelash extension tweezers ,rose gold tweezers ,eyebrow tweezers from Pakistan Alibaba.com
  http://www.alibaba.com/countrysearch/PK/tweezerman-tweezers.html
*  Aqua Medic Tweezers with Suction - AquaCave.com
Aqua Medic Tweezers with Suction - At AquaCave, we offer Best Prices, 5% Back, and Free Shipping on Aqua Medic Tweezers with Suction. - Buy Aqua Medic Tweezers with Suction - Now Only $24.95 - Aqua Medic tweezers are a useful tool for removing of hair algae. The tweezers are supplied with a hose to prevent plucked algae from floating around the tank. The hose can be connected to a canister filter or used for a water change.
  http://www.aquacave.com/aquarium-supplies/aquarium-tweezers/aqua-medic-tweezers-with-suction.html
*  OSA | Stable trapping and manually controlled rotation of an asymmetric or birefringent microparticle using dual-mode split...
Inserting a coverslip into half of a Gaussian laser beam at a suitable tilting angle can make the single-mode laser beam become closely spaced dual light spots at the laser focus. In this way, we can reform the conventional single-beam optical tweezers easily and construct a set of dual-mode split-beam optical tweezers, which can be used to manually rotate a trapped and twisted red blood cell around the optical axis. Furthermore, we demonstrate that the split-beam optical tweezers can also stably trap and orient a birefringent polystyrene micro strip particle, which otherwise will self rotate at a varying speed along the structural principal axes, fast spin about the optical axis in a tilting pose, or precess like a gyroscope, in the ...
  https://www.osapublishing.org/oe/abstract.cfm?URI=oe-18-14-14724
*  OSA | Axial potential mapping of optical tweezers for biopolymer stretching: the bead size matters
Optical tweezers (OT) are widely used for pico (and femto)-Newton range force measurements. The appropriate choice of the bead size is not well understood for biopolymer stretching applications of OT. We have shown, both by theory and experiment, that wrong choice of the bead size could cause errors as large as 295% in the measured force. We provide a simple map for correct choice of the bead size and the direction of pulling for such applications. There is a good agreement between our theoretical and experimental results.. © 2013 Optical Society of America. Full Article , PDF Article ...
  https://www.osapublishing.org/ol/abstract.cfm?uri=ol-38-5-685
*  OSA | Three-dimensional light-scattering and deformation of individual biconcave human blood cells in optical tweezers
For studying the elastic properties of a biconcave red blood cell using the dual-trap optical tweezers without attaching microbeads to the cell, we implemented a three-dimensional finite element simulation of the light scattering and cell's deformation using the coupled electromagnetic and continuum mechanics modules. We built the vector field of the trapping beams, the cell structure layout, the hyperelastic and viscoelastic cell materials, and we reinforced the constraints on the cell constant volume in the simulation. This computation model can be useful for studying the scattering and the other mechanical properties of the biological cells.. ©2013 Optical Society of America. Full Article , PDF Article ...
  https://www.osapublishing.org/oe/abstract.cfm?uri=oe-21-10-12174
*  Measuring droplet properties through passive microrheology in optical tweezers | (2009) | Bowman | Publications | Spie
We demonstrate the use of holographic optical tweezers to form arrangements of silica beads for trapping and measuring the mechanical properties of micron sized objects, such as oil droplets and yeast cells. This allows us to investigate the mechanical properties of the constrained object, which need not be optically trapped itself (thus preventing radiation damage and allowing objects with a low refractive index to be constrained). By compressing the object with the beads we are able to determine the size of the trapped object and show that there is an elastic coupling between the beads due to the presence of a trapped object. We expect more detailed analysis of the system will allow mechanical and frequency-dependent viscoelastic properties of objects to be investigated ...
  http://spie.org/Publications/Proceedings/Paper/10.1117/12.828139