Offered topics for Dissertations:

Thulium-doped fiber lasers

Supervisor: Pavel Peterka, Ph.D.

Teoretický a experimentální výzkum nových typů laserů s křemennými optických vlákny dopovanými thuliem, případně thuliem a yterbiem. Sestavení spektrálně, časově a prostorově rozlišeného numerického modelu vlákna. Teoretická optimalizace parametrů thuliem dopovaných optických vláken a dvouplášťových optických vláken dopovaných kromě thulia i yterbiem. Charakterizace vláken připravených v laboratoři optických vláken Ústavu fotoniky a elektroniky AV ČR nebo na spolupracujícím pracovišti na Univerzitě v Nice ve Francii. Spektroskopická charakterizace připravených vláken s použitím teoretického modelu. Experimentální ověření vybraných aplikací thuliem dopovaných křemenných optických vláken v laserech a zesilovačích v pásmech v okolí vlnových délek 800, 1470 nm a 2000 nm.

FIB SIMS: analytical method for nanotechnology

Supervisor: Jan Lorinčík, Ph.D.

FIB SIMS is a mass spectrometry technique, which is getting to the forefront of interest due to its potential in producing ion images with space resolution better than 100 nm. The technique is based on the bombardment of solid surfaces by accelerated Ga+ ions leading to the emission of secondary ions (reprezenting the surface composition), which are then mass spectrometrically analyzed.  In spite of the importance of the technique and the corresponding effort the mechanism of ion formation in SIMS has not been completely explained yet. The goal of the thesis is:

1. A systematic experimental study of the secondary ion formation at the bombardment of solids  by Ga+ ions and at its influencing by the flooding of oxygen and other gases
2. A suggestion of a secondary ion formation mechanism
3. A suggestion of experimental parameters (type of gas, its amount, setting of the ion gun, mass spectrometer) that will lead to an order of magnitude improvement of the secondary ion yield and thereby to the increase of the FIB SIMS sensitivity, which is necessary for the achievement of ion image resolution of several tens of nanometers.

The available facility is a new multifunctional instrument based on a scanning electron microscope, FIB-type ion gun, and the Time-of-Flight mass spectrometer.

Literature:

1. L. Frank, J. Král, Metody analýzy povrchů – iontové, sondové a speciální metody,  2002, Academia Praha
2. D. Briggs and M.P. Seah, Practical Surface Analysis – Ion and Neutral Spectroscopy, 1992, John Wiley and Sons
3. A. Benninghoven, F.G. Rüdenauer, H.W. Werner, Secondary Ion Mass Spectrometry – Basic concepts, instrumental aspects, aplications and trends, 1987 , John Wiley and Sons
4. L. A. Giannuzzi, F.A. Stevie, Introduction to Focused Ion beams – Instrumentation, Theory, Techniques and Practice, 2005, Springer
5. Nan Yao, Focused Ion beam Systems –Basics and Applications, 2007, Cambridge University Press

FIB: a manufacturing tool for nanostructures

Supervisor: Jan Lorinčík, Ph.D.

FIB SIMS is a modern physical tool for the creation of nanometer sized objects using a focused ion beam. Those nanoobjects can be formed either by the sputtering effect of the ion beam, when we talk about the nanomachining, or by locally inducing the decomposition of a properly chosen gas adsorbed on the sample surface, then nanoobjects can be grown

The goal of the thesis is a controlled creation of two- and three-dimensional nanostructures for photonic and sensoric applications. The starting type of the prepared nanostructure will be a Bragg grating  milled on the end and at the center of the optical fiber made from fused silica. 

The available facility is a new multifunctional instrument based on a scanning electron microscope, FIB-type ion gun producing Ga+ ions, and a computer controlled gas injection system. 

Literature:

1. L. A. Giannuzzi, F.A. Stevie, Introduction to Focused Ion beams – Instrumentation, Theory, Techniques and Practice, 2005, Springer
2. Nan Yao, Focused Ion beam Systems –Basics and Applications, 2007, Cambridge University Press