Off-axis prism resonator for improved beam quality of slab lasers

An off-axis prism resonator that was especially designed for slab lasers is investigated. It consists of an output coupling mirror and two 90-deg prisms, one of which is placed off axis. This arrangement permits a fill factor of one and reduces the mode order of the extracted beam compared with that of a conventional stable mirror resonator. Thus a high extraction efficiency and high beam quality are achieved.