Lei Zhang Knihy

This thesis examines laser generation from the ultraviolet to the short edge of the mid-infrared band by exploiting the nonlinear effects in photonic crystal fibers (PCFs). Several different physical mechanisms are investigated by using homemade PCFs with elaborately customized dispersion profiles. A particular focus is on the development of fiber optical parametric amplifiers (FOPAs) and oscillators (FOPOs) based on the PCFs with a zero-dispersion wavelength of ca.1.06 μm. In particular, several schemes are proposed for solving the key problems involved in the application of FOPOs. These oscillators can be made more convenient to use by optimizing the wavelength-tuning mechanisms and made more energy-efficient with the help of specially designed cavity structures. Today’s oscillators are more reliable, powerful and maneuverable than ever. This thesis provides a systematic road map in connection with the study of nonlinear wavelength generation in PCFs, from their fiber design and technical fabrication, to their physical mechanism and experimental investigation.

Magnetic molecules have attracted lots of interest. In this work, an ultra-stable and low noise scanning tunneling microscopy operating at 400 mK using He-3 (930 mK using He-4) has been developed. The magnetic behavior of different magnetic molecules on substrates, especially the exchange interaction between the magnetic ions, the magnetic anisotropy on the surface, the magnetic excitations as well as the Kondo effect, were studied by using STM.

Die Arbeit analysiert die drei wesentlichen Merkmale der gesprochenen Sprache: Prozesshaftigkeit, Multimodalität und Interaktivität. Anhand der Theorien von renommierten Linguisten wie Fiehler und Barden werden diese Eigenschaften detailliert untersucht. Konkrete Beispiele verdeutlichen, wie sich diese Merkmale in der Praxis manifestieren. Darüber hinaus werden auch weitere relevante Eigenschaften der gesprochenen Sprache betrachtet, die das Verständnis der primären Merkmale unterstützen und erweitern. Die Untersuchung bietet somit einen umfassenden Einblick in die Dynamik der mündlichen Kommunikation.