Speaker: Prof. Alexei Sokolov, Texas A&M University
Title: Controlled femtosecond laser filaments for remote sensing
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-phocusing 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. In a recent experiment we have used filaments for sub-diffraction-limited imaging of remote objects. Controlled production and manipulation of laser filaments will enable further applications to remote detection and sensing. In my talk, I will review the latest ideas and the most recent experimantal results from our work toward this goal.