Master Thesis Student
The Optical Communications Group at DLR-Oberpfaffenhofen investigates new technologies to increase the throughput in free-space optical links between ground stations, aircrafts, satellites, etc. The particular channel behavior due to atmospheric turbulence causes phase and amplitude distortions of the incident laser beam that lead to deviations in the signal direction and fluctuations in received power (so called “scintillations”). When transmitting a Gaussian laser beam profile, theory predicts an increase in the scintillation index when going from the axial position to off-axis beam locations. However, uncertainty exists for the region further off-axis than the 1/e2 beam radius. The exact knowledge of the far off-axis behavior is however crucial to anticipate and optimize optical link performance e.g. in feeder links to geostationary satellites.
The thesis shall comprise the following steps: Research on existing theory and reported verification experiments on off-axis scintillation index, and implementation of an according Matlab analysis script; Conception and implementation of a test-setup to measure tracked and untracked off-axis scintillation in a terrestrial scenario, allowing simultaneous observation of a large fraction of the beam profile; Analysis of measurements and comparison with theoretical models, possibly developing a model-extension if required.
Study of Electrical Engineering, Physics (or similar), Experience with hands-on electronics hardware work. Basics in Matlab programming, Interest in optics and free-space optical communications
Dr. Dirk Giggenbach, and Dr. Ramon Mata-Calvo
Possibility of pursuing PhD afterwards in a similar field of research.