Teramobile: A mobile femtosecond-terawatt laser and detection system

Abstract

International audienceWe describe the Teramobile system, a new mobile femtosecond multi-terawatt laser and detection system based on a state-of-the art CPA laser system embedded in a standard freight container, as well as a mobile detection unit allowing a characterization of the nonlinear propagation of high power laser pulses over long horizontal distances. The unique mobility feature of the whole system opens the way to previously unreachable applications for high-power laser pulses in the field of atmospheric research (lidar, laser-triggered lightning), which are also briefly reviewed

Optimal control of filamentation in air

“…The change in the filament onset is consistent with the positions observed for chirped pulse of similar duration. 8 In conclusion, we have demonstrated the optimization of nonlinear processes occurring over long distances in the propagation of multiterawatt laser pulses. Both the generation of visible wavelengths within the white-light continuum and the ionization efficiency at a fixed distance were increased by a factor of 2 and 1.4, respectively, by using optimal control procedures.…”

“…The experiments were performed using the Teramobile laser, 8 which delivered 150 fs pulses of 210 mJ centered around 785 nm at a repetition rate of 10 Hz. Light from the supercontinnum was scattered on a neutral diffusive screen located 36 m away from the laser and focused onto a photomultiplier by a 20 cm telescope installed close to the laser in a lidar configuration.…”

“…2͑b͔͒, which was observed to yield up to 20% more signal than could be obtained by tuning the grating compressor to optimize the chirp correction. 8 Maximizations of the white light at all wavelengths considered yield similar phase masks ͑i.e., the same optimal pulses͒, resulting in comparable relative signals at different wavelengths and similar spectra of the continuum around the fundamental ͑between 600 and 900 nm͒. This latter observation is unexpected, since different pulse shapes would result in different intensity gradient within the pulse envelope and hence in different broadening by SPM.…”

Laser femtoseconde, filamentation, nuage et orage

“…L'utilisation de laser de plus forteénergie tels que le Téramobile [29], premier laser femtoseconde-terawatt (400 mJ, 80 fs) mobile, pourrait conduireà des transmissions des filaments sur desépaisseurs optiques plusélevées encore. D'ores et déjà, des expériences en laboratoire ont montré que le déclenchement et le guidage par laser de décharges de haute tension restent possible sur 1,2 m, sous un flux de gouttes d'eau correspondant a une hauteur de précipitation de 1,4 mm/min, correspondantà une forte pluie [30].…”

Effects of atmospheric turbulence on remote optimal control experiments

“…Among the processes that may affect the propagation of an ultrashort laser pulse, thermal turbulence is likely the most effective in preventing remote control techniques. In fact, contrary to dispersion and Kerr-related effects, distortions induced by turbulence cannot be avoided by a sensible choice of the pulse characteristics, or precompensated, 8,9 due to their random nature. Pointing variation and wavefront distortions ͑speckles͒ of nanosecond or cw laser beams induced by atmospheric turbulence have been extensively studied.…”