A birefringence-compensated two-rod Nd:YAG laser operating in TEM00 mode with a CW 61W output power

Two identically pumped Nd:YAG rods with a imaging system and a polarization rotator are used in experiments to achieve a complete birefringence compensation. The measured depolarization ratio is from 1.0 to 2.5%, which increases with the increasing of pump power. With a TEM00-mode operation, the depolarization ratio achieved is less than 1%. A dynamically stable resonator is performed using two flat mirrors and an intra-cavity lens. 61 W linearly polarized output was achieved with a M (2) factor of 1.6, which is the state of the art for a lamp pumped laser.