National Repository of Grey Literature 123 records found  beginprevious74 - 83nextend  jump to record: Search took 0.00 seconds. 
SMV-2015-22: Samples of absorbing media for spectroscopy measurements
Lazar, Josef ; Hrabina, Jan ; Holá, Miroslava ; Oulehla, Jindřich ; Pokorný, Pavel
The content of this contractual research project for the company dealing with development of technology for enrichment of nuclear fission fuel was the design of samples of absorbing media for referencing of lasers for spectroscopy. The samples are absorbing cells with optical quality filled at various saturation temperatures. Thus the various pressure of saturated vapour was achieved.
SMV-2015-34: Development of a new optical method for barrel rifling straightness measurement
Holá, Miroslava ; Řeřucha, Šimon ; Oulehla, Jindřich ; Lazar, Josef
The aim of the project of the contractual research was to establish an optical lab for the measuring of barrel rifling straightness and to perform laboratory measurement of samples of ballistic barrels as well as analyse the measurement data. The used method is based on the laser measuring of straightness where side deviations of a beam are detected. These deviations are caused by deviations of the position of the retroreflector while it is shifted down the measured barrel. This retroreflector copies deviations of a barrel from straightness. The measured data were analysed with the help of our measuring software. The realization of the optical lab continues the previous performed study.
SMV-2015-24: Optical frequency references for laser spectroscopy
Hrabina, Jan ; Holá, Miroslava ; Oulehla, Jindřich ; Pokorný, Pavel ; Lazar, Josef
The contractual project was oriented to development and research of novel types of absorption cells for laser spectroscopy applications – these cells are intended for frequency stabilization of ultra-stable laser standards and investigation of spectral parameters of unknown liquids and gaseous environments. Novel methods for preparation of antireflection coatings on optical windows were investigated due to strict request for minimalization of optical losses and backreflections of interacting laser light at optical windows of the developed cells. Research of methods for thermal protection of the optical windows during the welding process was oriented to unique approach of inert gas jet cooling of AR coatings. Investigation of possibility of AR coatings homogenization was done by method of thermal baking at different temperature levels.
Frequency stabilization of DBR diode laser working on 633 nm for lenght metrology and spectroscopy
Pham, Minh Tuan ; Hucl, Václav ; Čížek, Martin ; Mikel, Břetislav ; Hrabina, Jan ; Řeřucha, Šimon ; Lazar, Josef ; Číp, Ondřej
Semiconductor lasers are nowadays very convenient and suitable for many applications in field of human activities. Mainly it is thanks to their small size, low cost and high energy efficiency. This work deals with frequency stabilization of DBR diode laser working on 633 nm and the measurements of its noise properties. For this purpose we have chosen DBR diode EYP-DBR-0633 from Eagleyard Photomic. This particular laser diode in temperature range from 6 degrees celsius to 24 degrees Celsius has a tuning range of 0,86 nm, which correspond to change of 650 GHz in optical frequency domain. In this paper we also present methodology and results for frequency noise properties investigation of this laser with unbalanced Mach-Zhender interferometer and 10 m long fibre spool inserted in reference arm.
Measurement of real-time gigacycle fatigue through real-time interferometry
Lazar, Josef ; Holá, Miroslava ; Hrabina, Jan ; Číp, Ondřej
We present an interferometric method for measurement of strain induced deformation of metal samples in experiments inducing high-cycle fatigue. The motivation is to get real-time information about the deformation of a metal sample under test, its elongation imposed by fast vibrating actuator. Fatigue of materials is a process of degradation of a material due to repeated application of forces which includes nucleation and propagation of cracks and leads to the failure of the component. It may appear in all parts of machines or structures which rotate, vibrate, are repeatedly loaded, are subjected to temperature gradients etc., so statistically, fatigue is implied in about 80% of all industrial failures.
Coordinate interferometric system for measuring the position of a sample of the electron lithograph
Holá, Miroslava ; Lazar, Josef ; Čížek, Martin ; Řeřucha, Šimon ; Číp, Ondřej
This project is called "Platform of advanced microscopic and spectroscopic techniques for nano and microtechnology." The coordinator of this project is the Brno University of Technology / Faculty of Mechanical Engineering and the co-investigators are ON Semiconductor Czech Republic, Ltd., Optaglio Ltd., Tescan Brno, Ltd. And the Institute of Scientific Instruments of the CAS, v. v. i.. In this project we are working on a design of an interferometric measuring system, laser source and detection techniques for a coordinate measuring system of the table of the electron beam lithography.
Distribution of the accurate optical frequency and time via photonic networks in the Czech Republic
Číp, Ondřej ; Čížek, Martin ; Pravdová, Lenka ; Hucl, Václav ; Řeřucha, Šimon ; Hrabina, Jan ; Lešundák, Adam ; Mikel, Břetislav ; Lazar, Josef ; Vojtěch, J. ; Smotlacha, V.
To verify the stability of the frequency of optical clock an intensive research in the transmission of stable frequency via optical fibers is in progress for many years. Interconnection of large cities and metropolitan networks with optical fiber running DWDM allowing to transfer many optical signals in parallel over one fiber at the same time contributes significantly to troubleshoot the problem. Between nodes of ISI Brno and the main center of CESNET there are several dedicated bi-directional channels through the DWDM technology. The first tests are ongoing with the transfer of accurate time, which are using the possibility of bi-directional communication over a single fiber, thus the phase delay including Doppler shift are reflected on the two signals as well. From periodic measurements can subsequently be evaluated daily, weekly and seasonal fluctuations of the delay and after deduction of such data from the measured data a mutual stability of used time normal can be determined. The second technique is a full compensation of phase of the laser wave through active control of phase changes of the wave during its transmission from the ISI to the node of CESNET. At present, a characterization of the behavior of individual system elements, including their commissioning is in progress.
SMV-2014-02: Set of absorption cells filled with precisely defined amount of the medium
Lazar, Josef
The research was oriented to technology of optical frequency references - absorption cells - demanded for laser standards frequency stabilization. Iodine absorption cells are commonly operated in regime of saturated vapour - the pressure of gaseous state part of absorbing media is regulated by the temperature control of solid phase part concentrated in cold finger of the cell. The novel approach is based on technology where the cell is filled to precisely defined absorbing media pressure. In this case the cell can be operated in regime where only gaseous iodine is presented, so the cell does not need to be thermostatized by external cooler. We realized a set of cells filled with different pressure levels of media corresponding to saturation temperatures range from -15 to +85 degrees of Celsius. The research also included development of novel techniques for filling the cells above the standard room temperatures.
SMV-2012-29: Absorption cell for laser interferometry
Lazar, Josef ; Hrabina, Jan
The research included investigation of spectral properties of molecular iodine absorption cell intended for ultra-precise laser interferometer referencing to primary standard of length. The cell was based on fused silica glass material which allowed us to reach ultra-pure absorption environment without negative foreign-gas distortion effects (collisional quenching, frequency stability degradation).
SMV-2012-28: Technology research of stabilization of optical frequency to reference transitions
Lazar, Josef ; Hrabina, Jan
The research was oriented towards custom design, optical technology processes, realization and testing of special optical frequency reference for realization of ultra-stable laser source for space-borne/orbital laser interferometer. The work included new technology steps evaluation and measurement of reachable spectral properties of realized reference.

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3 Lazar, Jan
2 Lazar, Jaroslav
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