Enhanced Lethality Using Self-Channeling Short-Pulse Lasers.

Ultrashort laser pulses have led to the development and demonstration of filamenting lasers, which make possible a vast array of new military and civil applications. These applications result from the filaments' novel ability to channel extremely highfluences through self-focussed channels in the atmosphere. The channels are ionized to electron densities, comparable to those of metals, and the filament (channel) diameter is roughy 100 microns. The laser intensity inside a filament is sufficient toionize air, while any condensed matter it contacts is devastated, including transparent or reflective materials. Recent theory and experiments suggest that filaments can be scaled up to tens of kilometers, containing tens of Joules. The abilitiy to crossvery complicated flow fields, including turbulence, shockwaves, and combustion environments makes filaments yet more attractive for long-range applications. This program will map the effects of ultra-intense laser pulses on materials of significantmilitary and commercial value, over a broad range of pulse parameters. The resulting data will allow not only the optimization of laser-ablation, tuned to these specific materials, it will also allow the identification of optimum lasers for specificmilitary missions. A natural commercial application is the ability to tune ultrashort laser pulses for optimized micromachining.