|
|
Measurement system for pulsed current source
Myška, Radek ; Križan, René (referee) ; Drexler, Petr (advisor)
This work deals with the description and analysis of suitable methods for measurement of non-periodical high-level current pulses. For pulsed current source design and development a suitable measurement system is required. In this work shunt resistor, Rogowski sensor and magneto-optic sensor are presented. The analysis of their properties is performed in order to design a suitable sensor for test current pulse measurement. A design of Rogowski coil sensor has been made. An experimental measurement of current pulses with short time relations has been performed. The suitability of the coil sensor for non-harmonic waveforms measurement has been evaluated on the basis of measurement results. In case of the magneto-optic sensor a concept utilizing an optical fiber has been proposed. The design of the sensor has been performed also. Individual parts of the sensor were verified. Experimental magneto-optic sensors have been built and their properties have been studied.
|
|
|
Workplace for testing of the photodiodes
Šedo, Ondrej ; Poliak, Juraj (referee) ; Wilfert, Otakar (advisor)
This paper is focused on design of the workplace for measuring basic parameters and characteristics of standard photodiodes. There is also experimental test of its possibilities and comparison of the measurement results with the catalogue data. It also includes elaboration of an algorithm that processes the measurement data into visual presentation.
|
|
|
Graphene photodetector based on plasmonic effects
Horáček, Matěj ; Hájková,, Zdenka (referee) ; Šikola, Tomáš (advisor)
Two rich and vibrant fields of investigation - graphene and plasmonics - strongly overlap in this work, giving rise to a novel hybrid photodetection device. The intrinsic photoresponse of graphene is significantly enhanced by placing the gold nanorods exhibiting unique anisotropic localized surface plasmon resonances on the graphene surface. The reported enhanced photoresponse of graphene is caused by the redistribution of localized surface plasmons in the nanoparticles into graphene. The exact underlying energy redistribution mechanism is thoroughly studied by a single particle scattering spectroscopy monitoring the particle plasmon linewidth as a function of the number of underlaying graphene layers. The obtained extraordinary plasmon broadening for nanoparticles placed on graphene suggests the contribution of a novel energy redistribution channel attributed to the injection of hot electrons from gold nanorods into graphene.
|
|
|
Workplace for testing of the photodiodes
Šedo, Ondrej ; Poliak, Juraj (referee) ; Wilfert, Otakar (advisor)
This paper is focused on design of the workplace for measuring basic parameters and characteristics of standard photodiodes. There is also experimental test of its possibilities and comparison of the measurement results with the catalogue data. It also includes elaboration of an algorithm that processes the measurement data into visual presentation.
|
|
|
Graphene photodetector based on plasmonic effects
Horáček, Matěj ; Hájková,, Zdenka (referee) ; Šikola, Tomáš (advisor)
Two rich and vibrant fields of investigation - graphene and plasmonics - strongly overlap in this work, giving rise to a novel hybrid photodetection device. The intrinsic photoresponse of graphene is significantly enhanced by placing the gold nanorods exhibiting unique anisotropic localized surface plasmon resonances on the graphene surface. The reported enhanced photoresponse of graphene is caused by the redistribution of localized surface plasmons in the nanoparticles into graphene. The exact underlying energy redistribution mechanism is thoroughly studied by a single particle scattering spectroscopy monitoring the particle plasmon linewidth as a function of the number of underlaying graphene layers. The obtained extraordinary plasmon broadening for nanoparticles placed on graphene suggests the contribution of a novel energy redistribution channel attributed to the injection of hot electrons from gold nanorods into graphene.
|
|
|
Measurement system for pulsed current source
Myška, Radek ; Križan, René (referee) ; Drexler, Petr (advisor)
This work deals with the description and analysis of suitable methods for measurement of non-periodical high-level current pulses. For pulsed current source design and development a suitable measurement system is required. In this work shunt resistor, Rogowski sensor and magneto-optic sensor are presented. The analysis of their properties is performed in order to design a suitable sensor for test current pulse measurement. A design of Rogowski coil sensor has been made. An experimental measurement of current pulses with short time relations has been performed. The suitability of the coil sensor for non-harmonic waveforms measurement has been evaluated on the basis of measurement results. In case of the magneto-optic sensor a concept utilizing an optical fiber has been proposed. The design of the sensor has been performed also. Individual parts of the sensor were verified. Experimental magneto-optic sensors have been built and their properties have been studied.
|
guest ::
