200-W Tm:YLF INNOSLAB laser

A Tm:YLF laser in INNOSLAB design is reported. It produces 200 W of output power at an optical efficiency of 24 % and a slope efficiency of 27 % with respect to incident pump power. The laser crystal is partially end-pumped in a tophat line focus with a width of 12 mm and a height of about 1 mm. It is placed in a stable, spherical laser resonator, which results in a highly elliptical output beam. The beam is near diffraction limit and Gaussian in shape in one axis and contains very high order transversal modes and is Top-Hat-like in shape in the other axis. The beam shape is ideal for pumping a Ho:YLF laser crystal in INNOSLAB design for a pulsed amplifier.