FAST COMPRESSION OF LASER BEAMS TO HIGHLY OVERCRITICAL POWERS

Laser beams can be strongly compressed in a plasma by stimulated Raman backscattering in a time short compared to the time scale for filamentation instabilities to develop. Such a compression should make feasible multi-MJ multi-exawatt-laser pulses technologically challenging by other means. The compression efficiency can reach nearly 100% at the Langmuir wave breaking limit. [S0031-9007(99)09280-7]