Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
UP: Fachverband Umweltphysik
UP 8: Methods 1
UP 8.1: Hauptvortrag
Mittwoch, 28. März 2012, 17:15–17:45, HFT-FT 131
From fs-LIDAR Sensing of the Atmosphere to fs-Optical Control — •Ludger Woeste1, Kamil Stelmaszczyk1, Roland Sauerbrey3, Jerome Kasparian2, and Jean PierreKamil Wolf2 — 1Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany — 2Université de Genève, GAP-Biophotonics, 1211 Geneva 4, Switzerland — 3Helmholtz Forschungszentrum Dresden-Rossendorf, 01328 Dresden, Germany
When launching sufficiently powered femtosecond laser pulses into the atmosphere, we observed extended (fs) bundles of white light emitting plasma filaments, which extended over km lengths. Their formation is based on a fascinating interplay of non-linear optical processes like Kerr-lensing, plasma-defocusing and self-phase modulation. The filaments emit directional white light in a wide spectral range from the IR to the UV, which allows the remote and simultaneous analysis of a rich variety of gaseous atmospheric constituents. Further, when they hit solid or liquid targets, they emit intensive characteristic plasma light, which allows the remote identification of soil, vegetation, waters and even radioactive isotopes deposited there on. Most interesting properties result from the electrical conductivity of such bundles of plasma-filaments. The effect allows not only to guide and control electric discharges and currents; it even provides a realistic chance to trigger lightning and to assist or initiate water condensation in the remote atmosphere.