The present disclosure relates to a laser crystal device (1) for short pulse lasers, comprising a container (4), the interior of which is sealed relative to the environment and which contains a technically pure atmosphere with windows (12, 13) in the side walls (12, 13) for the passage of laser radiation (16), which in operation passes through a laser crystal (6), wherein the window (12, 13) has an inclination of the Brewster angle to the beam path of the laser radiation (16) and a mounting (5) for the laser crystal (6) is provided within the container (4), the windows (12, 13) are inclined to each other by double the Brewster angle and are placed at an adequate distance from the laser crystal (6) position, with relation to the laser beam properties, wherein the beam cross section at the windows (12, 13) is sufficiently large in order to guarantee a peak intensity at the windows (12, 13) which is sufficiently reduced in relation to the peak intensity of the laser beam (16) at the laser crystal (6) for avoiding degenerative processes on the windows (12, 13).