Performance comparison of self-focusing with 1053-and 351-nm laser pulses

Hole boring characteristics of laser beams are studied using two different laser wavelengths in preformed plasmas with overdense regions. We have show n that a whole beam self-focusing is created in plasma with a considerable density scale length using a 1 mu m wavelength laser. The whole beam self-f ocusing of this type could be used for guiding the ultrahigh intense laser pulse to a highly compressed core for studying the feasibility of a fast ig nitor. There is a clear difference in the hole-boring characteristics betwe en two laser wavelengths at 1053 and 351 nm, both in the experiment and the simulation. Using the third-harmonic laser, a whole beam self-focusing is never created. The 351-nm laser beam broke up into filaments resulting in p lasma jets observed in our interferogram. [S1063-651X(99)06109-7].