Dr. Karel Witas Profile

Dr. Karel Witas

at VŠB-Technical Univ of Ostrava

SPIE Involvement:

Author

Publications (12)

Proceedings Article | 26 April 2019 Paper

Analysis of the effect of long-time thermal load on the total losses of the selected fiber-optic couplers

Karel Witas, Stanislav Zabka, Jaroslav Frnda, Martin Novak, Jakub Jalowiczor, Martin Stolarik, Rene Jaros

Proceedings Volume 11031, 110311D (2019) https://doi.org/10.1117/12.2519836

KEYWORDS: Fiber optics, Thermal effects, Thermography, Fiber optic communications, Telecommunications, Civil engineering, Optical components, Optics manufacturing, Optical testing, Biological research

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Proceedings Article | 11 April 2019 Paper

Perimetric monitoring: A comparison of a classical seismic sensor and fiber-optic interferometric sensor

Karel Witas, Martin Stolarik, Miroslav Pinka, Stanislav Zabka, Jakub Jalowiczor, Martin Novak, Rene Jaros

Proceedings Volume 11028, 110282K (2019) https://doi.org/10.1117/12.2522309

KEYWORDS: Sensors, Interferometry, Fiber optics sensors, Fiber optics, Seismic sensors, Fiber optics tests, Civil engineering, Mach-Zehnder interferometers, Interferometers, Acoustics

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Proceedings Article | 14 May 2018 Paper

Sensor system based on the Mach-Zehnder interferometer for the rail transport

Jan Nedoma, Marcel Fajkus, Radek Martinek, Karel Witas, Pavel Mec, Jan Jargus, Stanislav Hejduk, Petr Zavodny, Vladimir Vasinek

Proceedings Volume 10654, 106541G (2018) https://doi.org/10.1117/12.2304582

KEYWORDS: Sensors, Mach-Zehnder interferometers, Interferometry, Optical fibers, Interferometers, Fiber optics, Signal processing, Indium gallium arsenide, Telecommunications

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Proceedings Article | 14 May 2018 Paper

Analysis of encapsulation the fiber Bragg sensors for biomedical applications

J. Nedoma, M. Fajkus, J. Jargus, R. Martinek, Karel Witas, Jan Vanus, V. Vasinek

Proceedings Volume 10654, 106541F (2018) https://doi.org/10.1117/12.2304580

KEYWORDS: Sensors, Fiber optics sensors, Fiber Bragg gratings, Heart, Biomedical optics, Data acquisition, Biological research, Polymers, Composites, Glasses

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Proceedings Article | 16 May 2017 Paper

Analysis of the detection materials as resonant pads for attaching the measuring arm of the interferometer when sensing mechanical vibrations

Jan Nedoma, Marcel Fajkus, Radek Martinek, Ondrej Zboril, Lukas Bednarek, Martin Novak, Karel Witas, Vladimir Vasinek

Proceedings Volume 10231, 1023119 (2017) https://doi.org/10.1117/12.2257321

KEYWORDS: Interferometers, Sensors, Fiber optics sensors, Mechanical sensors, Signal processing, Fiber optics, Electromagnetic interference, Power supplies, Interferometry, Mach-Zehnder interferometers, Signal detection, Glasses, Photodetectors

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Proceedings Article | 16 May 2017 Paper

Analysis of the impact of the deposition optical fibers on the deformation measurement with a distributed system BOTDR

J. Nedoma, M. Fajkus, R. Martinek, J. Jargus, K. Witas, V. Vasinek

Proceedings Volume 10231, 1023118 (2017) https://doi.org/10.1117/12.2257065

KEYWORDS: Distributed computing, Standards development, Telecommunications, Optical fibers, Reflectometry, Fiber optics, Optical sensors, Optical networks, Sensor networks, Networks, Raman scattering, Rayleigh scattering, Scattering, Light scattering, Polymers

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Proceedings Article | 27 April 2017 Paper

Influence of different encapsulation types and shapes of polydimethylsiloxane on the temperature sensitivity of the FBG

J. Nedoma, M. Fajkus, R. Martinek, M. Novak, O. Zboril, J. Jargus, K. Witas, F. Perecar, V. Vasinek

Proceedings Volume 10208, 102080U (2017) https://doi.org/10.1117/12.2256716

KEYWORDS: Prototyping, Silicon, Dielectrics, Temperature metrology, Refractive index, Fiber Bragg gratings, Fiber optics sensors, Light emitting diodes, Optical fibers, Sensors, Analytical research, Shape analysis, Liquids, Light, Spectrum analysis

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Proceedings Article | 6 January 2015 Paper

Influence of DFB laser light on spectral properties of LDs and LEDs

Vladimír Vasinek, Petr Siska, Andrej Liner, Karel Witas, Stanislav Hejduk

Proceedings Volume 9450, 94501H (2015) https://doi.org/10.1117/12.2070588

KEYWORDS: Tunable lasers, Semiconductor lasers, Light emitting diodes, Light sources, Light, Fiber optics, Switches, Modes of laser operation, Optical pumping, Optical isolators

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Proceedings Article | 3 May 2013 Paper

Low noise omnidirectional optical receiver for the mobile FSO networks

Karel Witas, Stanislav Hejduk, Vladimir Vasinek, Jan Vitasek, Jan Latal

Proceedings Volume 8774, 87741Q (2013) https://doi.org/10.1117/12.2017086

KEYWORDS: Receivers, Photodiodes, Free space optics, Transmitters, Signal to noise ratio, Geometrical optics, Diodes, Sensors, Optical amplifiers, Amplifiers

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Proceedings Article | 3 May 2013 Paper

Rock massif temperature changes measurement with regard to thermal responses generated by a thermal response test device

Jan Latal, Jan Vitasek, Petr Koudelka, Petr Siska, Andrej Liner, Martin Papes, Karel Witas, Stanislav Hejduk, Vladimir Vasinek

Proceedings Volume 8774, 877416 (2013) https://doi.org/10.1117/12.2017241

KEYWORDS: Temperature metrology, Raman scattering, Optical fibers, Raman spectroscopy, Sensors, Scattering, 3D metrology, Wind energy, Thermal effects, Light scattering

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Proceedings Article | 19 October 2012 Paper

Simulation of fog influence on laser beam distribution in atmosphere

Vladimir Vasinek, Jan Latal, Petr Koudelka, Jan Vitasek, Karel Witas, Stanislav Hejduk

Proceedings Volume 8540, 85400Y (2012) https://doi.org/10.1117/12.977617

KEYWORDS: Fiber optic gyroscopes, Signal attenuation, Free space optics, Atmospheric optics, Atmospheric propagation, Atmospheric modeling, Gaussian beams, Optical simulations, Telecommunications, Transmittance

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Optical fibreless data networks P2P offer fast data transmissions with big transmittance from 1- 10 Gbps on a distance of 1- 6 km. Perfections of such networks are especially flexibility, rapid creation of communications. Sensitivity to atmospheric influences, necessity of light on sight belongs to disadvantages. Transmission through atmosphere be characterized by non-stationarity, inhomogeneity, the influences have random character. It means immediately that it is possible only with difficulty to project conclusions concerning to the measurement on one line upon fiberless line in another position. Contribution tackles a question of forming of the artificial hazy atmospheres, finding the statistical parameters of artificially created foggy atmospheres that could be reproduced to real environment. This work describes created laboratory apparatus powered with fog generator, heat source and ventilating fans, which allow in a controlled way to change the optical transmission inside the bounded space. Laser diode radiation at wavelength of 850 nm is transmitted into created space like this which is scanned with optical power meter after passing of artificially created turbulent vaporous environment. Changes in intensity of the passed lights are captured; the mean value and maximum deviation from the mean value are computed. In this way it is possible to change the reached specific attenuation in dB/km. Owing to turbulences it happens to deviations from the mean value, these abnormalities are characterized by the distribution function that describes the size of turbulences in time. By the help of ergodic theorem then it is possible to deduce that the distribution function of the foggy turbulences gained at continuous time evaluation has same history like the distribution function gained behind the same conditions in the setup in other times. It holds as well that these distribution functions are the same for variety of points in experimental space, provided there are well - kept the same conditions of turbulence creations. Contribution shows the experimental values, shapes of distribution functions, their influence on attenuation of fiberless communication lines and on achieved the transmission BER. At the present time the verification of conclusions is performed from the experimental model on outdoor connecting link working upon the distance of 1,3 km at the transmission rate of 1,25 Gbps.

Proceedings Article | 11 May 2012 Paper

Interaction between laser beams FP and DFB laser diodes

Vladimir Vasinek, Jan Latal, Petr Koudelka, Petr Siska, Jan Vitasek, Karel Witas

Proceedings Volume 8432, 84321U (2012) https://doi.org/10.1117/12.922136

KEYWORDS: Semiconductor lasers, Light emitting diodes, Phase modulation, Fiber lasers, Tunable lasers, Optical fibers, Optical isolators, Laser damage threshold, Structured optical fibers, Light sources

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Showing 5 of 12 publications

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