Beam smoothing techniques and focused beam profile
control techniques for high efficiency KrF laser fusion
are reported. We have developed 1D and 2D broadband random
phase (BRP) irradiation techniques. Our next idea is the
combination of a laser oscillator with a wide beam divergence
angle and phase plates. The wide divergence angle laser
beam eliminates the speckle patterns caused by the phase
plates. Well characterized focal spot patterns have been
observed with the front-end pulse of the Super-ASHURA KrF
laser system. Amplification experiments are on going.