Abstract

Ultrafast femtosecond laser pulses are able to deliver extreme local fields on point targets, avoiding avalanche ionization and any significant collateral damage. In the context of long range atmospheric propagation of multi-TW femtosecond laser pulses, the Ti:Sapphire laser has been the standard workhorse and has promoted atmospheric studies ranging from femtosecond LIDAR [1], remote LIBS [2], white light generation [3], discharge triggering and guiding [4], lightning control [5]. However, high density accumulated plasmas tend to strongly defocus the wavepacket and abruptly terminate individual filaments preventing their sustained long-range propagation. Despite the remarkable swath of applications that have been enabled with this ultra-intense laser source [6], the ability to launch a super-intense intact electromagnetic pulse over long distances remains elusive. The reason for this has been understood for some time and is due to the tendency of a relatively wide 800nm multi-TW beam to break up into tens or hundreds of light filaments with typical waists on the order of 100µm, originally initiated via modulational instability.

© 2015 IEEE