|
| |
|
|
Noise to signal transition: work obtained from noise studied by the optical tweezers
Šiler, Martin ; Filip, R. ; Jákl, Petr ; Brzobohatý, Oto ; Zemánek, Pavel
The noise-to-signal transitions are very interesting processes in physics as they might transform environmental noise to useful mechanical effects. In this contribution we introduce the problem of stochastic noise-to-signal transition of overdamped Brownian motion of a particle in the cubic potential. The particle reaches thermal equilibrium with its environment in the quadratic potential which is suddenly swapped to the cubic potential. We predict simultaneous increase of both the displacement and signal-to-noise ratio in the cubic potential for the position linearly powered by temperature of the particle environment. Further, we propose a feasible experimental setup for proof-of-the-principle experiment that uses methods of optical trapping in shaped laser beams providing cubic and quadratic potentials.
|
|
| |
|
|
Compact device for fluorescence measurement by optical fiber in microfluidic chip
Ježek, Jan ; Pilát, Zdeněk ; Zemánek, Pavel
In our paper we present a device that combines fluorescence spectroscopy with fiber optics. The device allows high speed detection (in the order of kHz) of the fluorescence signal, which is coming from the sample by an inserted optical fiber, e.g. from a micro-droplet flow in a microfluidic chip, from the liquid flowing in the transparent capillary, etc. The device uses a laser diode at a wavelength suitable for excitation of fluorescence, excitation and emission filters, optics for focusing the laser radiation into the optical fiber, and a highly sensitive fast photodiode for detection of fluorescence.
|
|
|
SMV-2013-19: Nanolithography system based on two-photon photopolymerization
Jákl, Petr ; Šerý, Mojmír ; Zemánek, Pavel
The reasearch contract deals with development of experimental setup for dynamic shaping of laser beams. Using computer generated holographic phase masks, it is possible to create independent foci of laser beams in the sample space, change their intensity profiles and power of each diffracted beam. By employing fast acousto-optic modulator, the complex procedure allows control of sample irradiation within microsecond resolution. It is possible to precisely select sample region for laser impact using computer-controlled nano-positioning stage.
|
|
|
SMV-2012-07: Optical tweezers
Zemánek, Pavel ; Jákl, Petr ; Šerý, Mojmír
We developed unique system combining holographic optical tweezers with Raman microspectrometer. Part of the contract research was also laboratory desktop consisting of compact optical tweezers and optical scissors combined with light microscope. Delivery included user friendly program enviroment to fully control all features of provided devices.
|
|
|
From the mere pushing to sorting of microparticles and assembly of microrobots by light
Zemánek, Pavel ; Arzola, Alejandro V. ; Brzobohatý, Oto ; Chvátal, Lukáš ; Jákl, Petr ; Kaňka, Jan ; Karásek, Vítězslav ; Šerý, Mojmír ; Šiler, Martin
We demonstrate the recent progress in the field of optical micromanipulation. We start with the classical applications of solar sail propelled by the radiation pressure and approach the recent ones dealing with optical tractor beams, optical binding and sorting of microobjects. The pioneering attempts to assemble a microrobot by light is presented.
|
|
|
Specific forms of users interaction with holographic optical tweezers controlled by leap motion
Keša, P. ; Tomori, Z. ; Kaňka, Jan ; Jákl, Petr ; Šerý, Mojmír ; Bernatová, Silvie ; Antalík, M. ; Zemánek, Pavel
Optical tweezers allows contactless three-dimensional manipulation with electrically neutral objects of sizes from tens of nanometers to tens of micrometers. Mouse or joystick are the traditional devices to control the positions of trapping beams in holographic optical tweezers that provide optical manipulation with microobjects. Our approach is based on a modern 3D depth sensors combined with gestures and speech recognition software. The human operator controls the position of one trapping beam by a traditional pointing device like mouse or joystick. However, manipulation with more objects needs control of corresponding number of independent trapping beams generated by a spatial light modulator. We upgraded own NUI software which processes signals from sensors and sends the control commands to holographic Raman tweezers which subsequently controls the positions of trapping microparticles and the acquisition system of Raman spectra.
|
|
|
Main Activites of the Institute of Scientific Instruments
Müllerová, Ilona ; Radlička, Tomáš ; Mika, Filip ; Krzyžánek, Vladislav ; Neděla, Vilém ; Sobota, Jaroslav ; Zobač, Martin ; Kolařík, Vladimír ; Starčuk jr., Zenon ; Srnka, Aleš ; Jurák, Pavel ; Zemánek, Pavel ; Číp, Ondřej ; Lazar, Josef ; Mrňa, Libor
Institute of Scientific Instruments (ISI) was established in 1957 to develop diverse instrumental equipment for other institutes of the Academy of Sciences. ISI has long experience in research and development of electron microscopes, nuclear magnetic resonance equipment, coherent optics and related techniques. Nowadays the effort concentrates on scientific research in the field of methodology of physical properties of matter, in particular in the field of electron optics, electron microscopy and spectroscopy, microscopy for biomedicine, environmental electron microscopy, thin layers, electron and laser beam welding, electron beam lithography using Gaussian and shaped electron beam, nuclear magnetic resonance and spectroscopy, cryogenics and superconductivity, measurement and processing of biosignals in medicine, non-invasive cardiology, applications of focused laser beam (optical tweezers, long-range optical delivery of micro- and nano-objects) and lasers for measurement and metrology. ISI works both independently and in cooperation with universities, other research and professional institutions and with private companies at national and international level.
|
|
|
Raman tweezers for sorting of living cells
Pilát, Zdeněk ; Ježek, Jan ; Kaňka, Jan ; Šerý, Mojmír ; Jákl, Petr ; Zemánek, Pavel
We have developed an instrument for automatized analysis and sorting of living cells of unicellular algae and other micro-objects based on laser tweezers and Raman spectroscopy. The system comprises the Raman tweezers setup, special microfluidic chip, and a specialized software allowing image recognition, spectral analysis, and automated sorting functions. The resulting instrument allows non-destructive analysis of chemical properties of living cells and their automatic separation for further examination or cultivation.
|
guest ::
RSS feed.