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Classical and quantum model of 1D dynamics of free electron in ponderomotive potential of an optical beat wave
Kuchař, Marek ; Kozák, Martin (advisor) ; Chlouba, Tomáš (referee)
Inelastic scattering of freely propagating electrons on light waves is currently a studied topic because of potential applications in advanced electron microscopy and diffraction. The interaction is typically described using an approximation, in which we assume that the electron's velocity nearly does not change during the interaction. In this thesis we aim to describe the dynamics of electrons in an interaction potential generated by an optical wave beyond this regime. In classical description we solve the nonlinear equation of motion and while addressing the problem using quantum mechanical description we first use parabolic approximation of the interaction potential and then we also study the evolution of a free electron wavefunction in a full periodic potential. Using numerical simulations we show the expected evolution of the electron spectra during the interaction, based on analytical solutions. 1
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Ultrafast laser spectroscopy of semiconductor nanostructures
Chlouba, Tomáš ; Trojánek, František (advisor) ; Žídek, Karel (referee)
In this work we investigate changes in dynamics of CdSe nanocrystalline films caused by different annealing temperatures and different conditions during films growth. We use methods of time-resolved laser spectroscopy like time-resolved pump and probe and streak camera to study these dynamics. We also measured linear absorption and luminiscence. Our goal is to match measured dynamics with dynamics of other samples with different annealing temperatures and discuss the microscopic origin of these dynamics. Powered by TCPDF (www.tcpdf.org)
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Study of optical nonlinearities in semiconductors and semiconductor nanostructures
Chlouba, Tomáš ; Trojánek, František (advisor) ; Filip, Radim (referee) ; Herynková, Kateřina (referee)
In the main part of this thesis I study the relaxation mechanisms of charge carriers in silicon nanocrystals in SiO2 matrix. One of the potential applications of these structures lies in photovoltaics, specifically in construction of all-silicon tandem solar cells. I studied the dynamics of carriers in these structures by methods of ultrafast spectroscopy which helped to unravel the microscopic behaviour of carriers, their transport, localization etc. Furthermore I investigated the doping of such structures as the technology of doping is crucial for manufacture of pn- junctions which are the core component of solar cells. At the end I delve into the dissipative Jaynes-Cummings model by mathematical modeling and theoretical calculations which describes among others microlasers and as such comes under a field of cavity quantum electrodynamics.
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Investigation of parameters of ultrafast laser pulses
Chlouba, Tomáš ; Němec, Petr (advisor) ; Preclíková, Jana (referee)
In this work we investigate parameters of laser radiation coming from continual titan-sapphire laser 3900S, pulsed titan-sapphire laser Mai-Tai HP and from optical parametric oscillator Inspire made by Spectra Physics. We are particulary insterested in dependence of power, width of the beam, noise and beam pointing stability as a function of wavelength. We have also measured beam pointing stability in time and compared it with beam stability during change of wavelength. With pulse laser we are also interested in the spectra and time width of the pulses. We aim to compare the properties of both titan-sapphire lasers and to verify specifications of Mai-Tai and Inspire given by the manufacturer.
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Ultrafast laser spectroscopy of semiconductor nanostructures
Chlouba, Tomáš ; Trojánek, František (advisor)
In this work we investigate changes in dynamics of CdSe nanocrystalline films caused by different annealing temperatures and different conditions during films growth. We use methods of time-resolved laser spectroscopy like time-resolved pump and probe and streak camera to study these dynamics. We also measured linear absorption and luminiscence. Our goal is to match measured dynamics with dynamics of other samples with different annealing temperatures and discuss the microscopic origin of these dynamics. Powered by TCPDF (www.tcpdf.org)
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Study of optical nonlinearities in semiconductors and semiconductor nanostructures
Chlouba, Tomáš ; Trojánek, František (advisor) ; Filip, Radim (referee) ; Herynková, Kateřina (referee)
In the main part of this thesis I study the relaxation mechanisms of charge carriers in silicon nanocrystals in SiO2 matrix. One of the potential applications of these structures lies in photovoltaics, specifically in construction of all-silicon tandem solar cells. I studied the dynamics of carriers in these structures by methods of ultrafast spectroscopy which helped to unravel the microscopic behaviour of carriers, their transport, localization etc. Furthermore I investigated the doping of such structures as the technology of doping is crucial for manufacture of pn- junctions which are the core component of solar cells. At the end I delve into the dissipative Jaynes-Cummings model by mathematical modeling and theoretical calculations which describes among others microlasers and as such comes under a field of cavity quantum electrodynamics.
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Ultrafast laser spectroscopy of semiconductor nanostructures
Chlouba, Tomáš ; Trojánek, František (advisor)
In this work we investigate changes in dynamics of CdSe nanocrystalline films caused by different annealing temperatures and different conditions during films growth. We use methods of time-resolved laser spectroscopy like time-resolved pump and probe and streak camera to study these dynamics. We also measured linear absorption and luminiscence. Our goal is to match measured dynamics with dynamics of other samples with different annealing temperatures and discuss the microscopic origin of these dynamics. Powered by TCPDF (www.tcpdf.org)
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Ultrafast laser spectroscopy of semiconductor nanostructures
Chlouba, Tomáš ; Trojánek, František (advisor) ; Žídek, Karel (referee)
In this work we investigate changes in dynamics of CdSe nanocrystalline films caused by different annealing temperatures and different conditions during films growth. We use methods of time-resolved laser spectroscopy like time-resolved pump and probe and streak camera to study these dynamics. We also measured linear absorption and luminiscence. Our goal is to match measured dynamics with dynamics of other samples with different annealing temperatures and discuss the microscopic origin of these dynamics. Powered by TCPDF (www.tcpdf.org)
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Investigation of parameters of ultrafast laser pulses
Chlouba, Tomáš ; Němec, Petr (advisor) ; Preclíková, Jana (referee)
In this work we investigate parameters of laser radiation coming from continual titan-sapphire laser 3900S, pulsed titan-sapphire laser Mai-Tai HP and from optical parametric oscillator Inspire made by Spectra Physics. We are particulary insterested in dependence of power, width of the beam, noise and beam pointing stability as a function of wavelength. We have also measured beam pointing stability in time and compared it with beam stability during change of wavelength. With pulse laser we are also interested in the spectra and time width of the pulses. We aim to compare the properties of both titan-sapphire lasers and to verify specifications of Mai-Tai and Inspire given by the manufacturer.
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