Patent ID: 7203211

Claim:
Device for the optical excitation of laser-active crystals, with a diode laser ( 1 ) which generates pump radiation ( 2 ), the laser-active crystal being arranged in a solid-state laser or solid-state laser amplifier and the laser-active crystal having an axis (C) with strong absorption and an axis (A) with weak absorption, comprising: an optical element ( 4 ) is arranged downstream of the diode laser ( 1 ) in order to achieve spatial shaping of the pump radiation from the diode laser ( 1 ) and in that the pump radiation ( 2 ) from the diode laser ( 1 ) is substantially polarised linearly in a privileged polarisation direction, and in that the polarisation direction of the pump radiation ( 2 ) is oriented parallel to the weak-absorption axis (A) of the laser-active crystal ( 14 ) when it is incident in the laser-active crystal ( 14 ); and wherein the laser-active crystal ( 14 ) has at least a first and a second end face ( 14 a , 14 b ) which have a polarisation-dependent transmission, and in that the polarisation direction of the pump radiation ( 2 ) is oriented so that the reflection losses at the first or second end faces ( 14 a , 14 b ) are minimal and the optical power which enters the laser-active crystal ( 14 ) is maximal.