Semimonolithic Nd:YAG ring resonator for generating cw single-frequency output at 1.06 microm

We report 2.1 W of unidirectional single-frequency laser output from a novel Nd:YAG ring laser longitudinally pumped by a laser diode bar. The resonator requires only a single discrete optic and magnet, in addition to the laser medium, for stable multiwatt single-frequency operation. Undoped YAG is diffusion bonded to the Nd:YAG laser crystal at the pump face to eliminate residual spatial hole burning and improve thermal conductivity. This new laser design can be scaled to higher powers through more facile diode access and is useful for cw intracavity doubling.