Laser systems

Abstract

Apparatus for improving properties of a solid material by providing shock waves therein. A laser oscillator 10a provides a plurality of pulses 112 of coherent radiation. The leading edge of each pulse is sharpened either by a metal foil 18 or by phase conjugation reflection means 18a, 18e including a stimulated Brillouin scattering cell 18d,18e and optionally a Faraday isolator 18b. Each pulse is directed onto an amplifier 123 comprising first and second laser amplifier rods 23a,23b in series. At least a major portion of the radiation 112 amplified by the first amplifier rod 23a is directed to the second amplifier rod 23b, where it is amplified and then directed to a surface of the solid material. Substantially uniform spatial amplitude is achieved in the radiation 112 in at least one of these ways: A pair of flashlamps 70,71 are included with each laser amplifier rod 23a,23b for pumping the rod; the axis of each flashlamp 70,71 and the axis of the first rod 23a are substantially parallel to each other and substantially in the same (first) plane; and a (second) plane containing the axis of the second rod 23b and the parallel axes of its associated flashlamps 70,71 is substantially perpendicular to the first plane; and/or the oscillator 10c provides a beam of unpolarized coherent radiation 12T in which the spatial amplitude pattern of each succeeding pulse is substantially a mirror image of the pattern in the pulse that preceded it, or is rotated about its axis by a predetermined smaller angle from the pattern in the pulse that preceded it.

Dependencies are inferred from the claim text.