The subject of this thesis is the exploration of new concepts for compact solid-state lasers in the visible and near-infrared spectral range using new components such as volume Bragg gratings for wavelength stabilisation and wavelength tuning. Also single-walled carbon nanotubes for mode-locking and Q-switching of lasers have been studied.We have developed a new method for the tuning of solid-state lasers by replacing a dielectric mirror with a transversally chirped volume Bragg grating, which allows smooth wavelength tuning without additional elements inside the laser cavity. The result is a more compact laser, since the tuning mechanism and output coupler are incorporated in one component. Another benefit is an increased efficiency, since additional elements inside the cavity will always add to the total loss of the laser. This has been demonstrated for a broadband ytterbium laser around 1 µm and a single-longitudinal-mode Nd:YVO4 laser around 1.06 µm. A volume Bragg grating has also been used to construct an efficient, narrow-linewidth ytterbium fiber laser and the employment of a volume Bragg gratingas the pump mirror of a solid-state laser for frequency-doubling has been investigated. Both lasers represent a practical solution, eliminating the use of additional intracavity elements. Second-harmonic generation is an efficient way to access the visible spectral range using diode-pumped solid-state lasers. However, these lasers can suffer from large amplitude fluctuations, which has been analyzed in more detail for an optically-pumped semiconductor disk-laser and a volume Bragg grating locked ytterbiumlaser. The control of those amplitude fluctuations is very important, since many applications like fluorescence microscopy require a laser with a constant output power and as little noise as possible. In addition to this, we have demonstrated, that saturable absorbers based on quan-tum dots and carbon nanotubes can be used to mode-lock compact laser at a wavelength around 1.03 µm. Those lasers have many interesting applications incommunications, clock generation, metrology and life sciences. / <p>QC 20130507</p>

Background: Globalization, technological advancement and opportunity of capturing new markets have pushed business organizations to expand their business in the inter- national market. As a result, companies have established their subsidiaries in the host country and control their business from headquarters. Moreover, headquarters provide all the support such as training, strategies and knowledge to their subsidiary to perform better and help to build competitive advantage. The importance of knowledge transfer has increased in recent decades because knowledge is considered as an asset. Aim: The aim of the study is to analysis the method of knowledge transfer (explicit and tacit) from multinational companies headquarter to their subsidiaries. Methodology: In this paper, qualitative research approach has been followed with con- tent analysis technique. Primary data has been collected through interviews and Conve- nience sampling technique were used. Findings: Findings of the study shows that MNCs are using agency theory and knowl- edge base theory to transfer knowledge to their subsidiary. Most of the cases it has been observed that headquarters appeared as a knowledge creator whereas subsidiaries only utilize that knowledge. Moreover, manufacturing based companies transfer more explicit knowledge and service based companies transfer more tacit knowledge. Almost every MNCs use training, seminars, creating social groups and written instructions to transfer explicit and tacit knowledge to their subsidiaries. Study also found that there are some internal (hoarding behavior, non-invented here syndrome) and external factors (culture, language, location) which affect the knowledge transfer process of MNCs. Contribution of the study: This study will help managers around the world to under- stand the core concept of knowledge transfer, knowledge transfer method and factors affecting knowledge transfer. On the other hand, it will also help to design flawless channels to transfer knowledge. Scope of further studies: More interviews can be added including managers from the subsidiaries to get a more broader perspective. Also the studies can be done with com- paring different industries since knowledge is different depending on the industry. For example, the service Industry has more tacit knowledge than in the manufacturing indus- try.