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Preparation of LiNbO3 nanostructures and their characterization
Pikna, Štěpán ; Jelínek, Michal (referee) ; Dvořák, Petr (advisor)
This master thesis is focused on the deposition of LiNbO3 on c-cut Al2O3 substrate. This material exhibits an electro-optic effect, which refers to the change in the refractive index upon the application of an external voltage, and it has extensive applications in electro-optic modulators. Currently, there is significant interest in miniaturizing these devices for use in the fields of meta-optics and photonics, where its transparency is also advantageous. The first part of this thesis is dedicated to a review of the electro-optic effect and its application in optical metasurfaces. Subsequently, the review addresses the pulsed laser deposition of LiNbO3. The practical part begins with the optimization of target fabrication from LiNbO3 wafers using a laser cutter. Following this, the measurement of the electro-optic effect from a monocrystalline LiNbO3 wafer is discussed. The final section is devoted to the deposition of this material onto a sapphire substrate and further analysis using SPM, XPS, XRD, and SEM. Monocrystalline growth of 30 nm grains was observed, and the physical dependencies of the growth was studied.
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Electrooptic Pockels effect in X-ray radiation detectors
Rejhon, Martin ; Franc, Jan (advisor) ; Moravec, Pavel (referee)
In this work, we have added a temperature controller to an apparatus for measuring Pockels effect, which comprises of an integrated circuit and a Peltier element. Then the course of the electric field was measured in the sample of high resistance CdTe, a suitable detector on the high-energy radiation, depending on the voltage and temperature of the sample. Also the charge distribution in the sample was determined depending on time after the voltage and sample's temperature were reached. Finally, the activation energies of deep levels were determined, which are responsible for the polarization. Powered by TCPDF (www.tcpdf.org)
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Electrooptic Pockels effect in X-ray radiation detectors
Rejhon, Martin ; Franc, Jan (advisor) ; Moravec, Pavel (referee)
In this work, we have added a temperature controller to an apparatus for measuring Pockels effect, which comprises of an integrated circuit and a Peltier element. Then the course of the electric field was measured in the sample of high resistance CdTe, a suitable detector on the high-energy radiation, depending on the voltage and temperature of the sample. Also the charge distribution in the sample was determined depending on time after the voltage and sample's temperature were reached. Finally, the activation energies of deep levels were determined, which are responsible for the polarization. Powered by TCPDF (www.tcpdf.org)
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