SEMINÁRIO DO LMCAL
“Controlled femtosecond laser filaments for remote sensing”
Prof. Dr. Alexei V. Sokolov Stephen E. Harris Professor of Quantum Optics, Texas A&M University
10 de agosto, quarta-feira, Sala 335, Ala II, Ed. Principal, às 15h30
Abstract - Femtosecond laser filamentation starts when Kerr-induced self-focusing overcomes beam diffraction. When a threshold power is reached, the transverse intensity profile of the laser beam decreases until nonlinear defocusing mechanisms come into play, due to for example production of plasma or multiphoton excitation of conduction-band electrons. The balance between self-focusing and defocusing processes results in formation of a filament that can propagate over distances orders of magnitude longer than the Rayleigh range corresponding to their transverse dimensions. We have used filaments for subdiffraction-limited imaging of remote objects. In addition, filament-induced breakdown spectroscopy allows remote identification of trace elements. Controlled production and manipulation of laser filaments will enable further applications to remote detection and sensing. In my talk I will review the ideas and the experimental results from our work toward this goal.
