A high extraction efficiency laser system. The novel laser system includes a master oscillator for providing a laser beam, an amplifier adapted to amplify the laser beam, and an aberrator for aberrating the laser beam to prevent the formation of caustic intensity patterns within the amplifier. In an illustrative embodiment, the laser system also includes a depolarizer disposed between the master oscillator and the amplifier to reduce the contrast of speckle intensity patterns in the amplifier, and a mechanism adapted to rotate or otherwise move the aberrator to time-vary the aberrations in the beam in order to increase the spatial homogenization of saturation and extraction patterns in the amplifier. In a preferred embodiment, the coherence length of the beam is also shortened to reduce interference fringes in the amplifier.