Spaceborne laser filamentation for atmospheric remote sensing

A proof-of-concept of space-borne laser filamentation for atmospheric remote sensing is presented. The remote generation of laser filaments from an Earth-orbiting satellite is shown by numerical simulations to be theoretically possible for a large range of laser parameters. The model includes a realistic representation of the stratified atmosphere and accounts for multi-species ionization and the dependence of air density upon the molecule type and altitude profile. The remote generation of a white light continuum extending from 350 nm to 1.1 mu m within the filament is demonstrated, and hereby proposed as an atmospheric in-situ light source for monitoring greenhouse gases and pollutants on a global scale by light detection and ranging (lidar) techniques. Scaling laws are also derived for estimating the filament altitude as a function of peak pulse power (3 GW-3 TW), beam radii (10-200 cm) and for three different curvatures (300, 390, 500 km) for femtosecond infrared (800 nm) pulses. We find that operating conditions for remote supercontinuum generation are already available with current ground-based mobile laser technology and within reach of future space laser systems.