A laser amplifier head is provided. The laser amplifier head includes a plurality of plates of a solid-state laser active medium disposed in a housing, arranged parallel to one another with their main surfaces facing one another, the housing being provided with an inlet port and an outlet port for a cooling liquid, and also at least one window allowing a laser beam to pass through the laser active medium plates, wherein it also includes:



a mechanical connection device allowing a cyclic movement at least of the laser active medium plates in relation to the laser beam in a plane (xy) perpendicular to the direction (z) of their thickness; and
cooling liquid guide plates arranged in the extension of the laser active medium plates, between the latter and the inlet port of said liquid.