A solid body laser has a crystal disk forming its laser active medium. A
flat side of the crystal disk is totally reflecting. A resonator mirror
configuration includes a partially transparent end mirror and one or more
folding mirrors, which are disposed with spatial separation from the
crystal disk, and the optical axes of the mirrors extend in an inclined
manner on the central axis of the crystal disk in such manner that the
laser beam which is diffused inside the resonator mirror configuration
impinges upon the folding mirror at an oblique angle.