Retired Professor Dr. Nikolaus Schwentner
This group applies energy to solid and fluid bodies by means of light and examines the processes through which the energy is then redistributed within the system. To achieve this, ultra-short laser pulses are used within the lab and synchrotron radiation is applied at BESSY II. A series of experiments are being conducted on noble gas crystals with embedded molecules because these systems can be treated well from a theoretical standpoint. The group is currently working on the following areas of focus:
- Analysis and control of photochemical reactions: The vibrations of embedded molecules are measured in real time using laser pulses and their damping determined through collisions with the crystal surroundings. The breakage of bonds, the movement of the fragments within the crystal, and recombination are tracked over time. The molecules are oriented using highly polarized laser fields in order to control the processes.
- Applications for short-wave lasers: Within the noble gas crystals, high densities of excited molecule complexes are produced and then emit ultraviolet radiation. Amplification processes and laser effects are examined using these complexes.
- Structuring through photochemical etching: Halogens are deposited in layers on surfaces, and short-wave radiation is used to trigger photochemical processes that lead to stripping of the material at the illuminated locations. The efficiency and quality of mapping of templates are studied with regard to lithographic applications.