Generation of powerful filaments at a long distance using adaptive optics

摘要

Because of its extraordinary properties (intensity clamping, white light source, km long plasma channels), filamentation represents an ideal candidate for remote sensing. However, the promising generation of filaments at long distances for such purposes remains an issue. We propose a specially designed focusing telescope to properly deliver the laser pulses at long distance and generate powerful filaments. The telescope includes a deformable mirror (DM) that corrects the wavefront's aberrations working in a closed loop system with a wavefront sensor (WFS). Using this setup we are able to generate extraordinarily strong nitrogen signals at a distance as far as 90 m using 40 mJ laser pulses. Compared to the chirped based filament control technique, we believe that an appropriate control of the reservoir like what we have achieved will contribute to reduce the energy of the required laser pulses and at the same time, the cost of the required laser system.