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Preparation and characterization of crystalline materials - salts of N-guanylglycinium and guanidinium
Skopalík, Jiří ; Matulková, Irena (advisor) ; Zákutná, Dominika (referee)
The scope of this bachelor thesis is the preparation and study of new salts, which can be obtained from systems N-guanylglycine - inorganic acid and guanidine - amidosulfuric acid, as new materials with potential for applications in nonlinear optics. Prepared crystalline salts of N-guanylglycinium - i.e. chloride, two hydrogenphosphites and sulfate dihydrate along with guanidinium amidosulfate were characterized by methods of vibrational spectroscopy (infrared and Raman) and X-ray diffraction (single crystal and powder methods). To estimate the nonlinear optical properties and for the interpretation of the vibrational manifestations of N-guanylglycinium cation, quantum-chemical calculations were performed. Finally, for two non-centrosymmetric N-guanylglycinium hydrogenphosphites, the efficiency of second harmonic generation was determined for powder samples.
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Investigation of new materials for second harmonic generation
Brajer, Martin ; Němec, Petr (advisor) ; Žídek, Karel (referee)
In these bachelor thesis optical properties of materials are studied. This materials are purposefully prepared for effective second harmonic generation (SHG) and for its usage in optoelectronics. Specificely we will measure the first hyperpolarizibility. Non-coherent phenomenon of hyper-Rayleigh scattering will be used. Considering its incoherence, the effect is very weak. It's necessary to use a strong source of light, pulse laser and a sensitive detection device, photomultiplier. Samples are prepared in cooperating chemical laboratories of Faculty of Science of Charles University in Prague. Additionally, we will discuss participation of two-photon fluorescence in output intensity because of its interchangeability with SHG.
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Krystalové inženýrství nových materialů pro nelineární optiku
Fridrichová, Michaela ; Němec, Ivan (advisor) ; Černošek, Zdeněk (referee) ; Schwendt, Peter (referee)
This thesis focuses on preparation of novel compounds suitable for nonlinear optics (NLO). In particular, the target property is the second harmonic generation (SHG) and the group of interest are salts of the cations with delocalized electrons which can serve as carriers of the NLO properties. In particular, four derivatives of the highly interesting molecule of guanidine were selected and their NLO potential was proven by quantum chemical computations. In total, twenty new structures were described and those with the noncentrosymmetric structure assembly were examined for the SHG efficiency. Four of the prepared compounds exhibited a noticeable SHG efficiency, two of them even comparable to urea. The most promising compound, the guanylurea hydrogen phosphite (GUHP), was examined in more detail while many interesting NLO properties were revealed. The results of this work are presented also in 10 attached publications which are an integral part of the thesis. Keywords: nonlinear optics, second harmonic generation, guanidine derivatives, guanylurea, N-phenylbiguanide, N,N-dimethylbiguanide, N,N,N˝-triphenylguanidine
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Investigation of new materials for second harmonic generation
Brajer, Martin ; Němec, Petr (advisor) ; Žídek, Karel (referee)
In these bachelor thesis optical properties of materials are studied. This materials are purposefully prepared for effective second harmonic generation (SHG) and for its usage in optoelectronics. Specificely we will measure the first hyperpolarizibility. Non-coherent phenomenon of hyper-Rayleigh scattering will be used. Considering its incoherence, the effect is very weak. It's necessary to use a strong source of light, pulse laser and a sensitive detection device, photomultiplier. Samples are prepared in cooperating chemical laboratories of Faculty of Science of Charles University in Prague. Additionally, we will discuss participation of two-photon fluorescence in output intensity because of its interchangeability with SHG.
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