Performance of a low-loss pulsed-laser deposited Nd:Gd3Ga5O12 waveguide laser at 1.06 and 0.94 mu m

We report the laser performance of a low-propagation-loss neodymium-doped Gd3Ga5O12 (Nd:GGG) waveguide fabricated by pulsed-laser deposition. An 8-mu m-thick crystalline Nd:GGG film grown upon an undoped Y3Al5O12 substrate lases at 1.060 and 1.062 mu m when pumped by a Ti:sapphire laser operating at 740 or 808 nm. Using a 2.2% output coupler, we observed a 1060-nm laser threshold of 4 mW and a slope efficiency of 20%. Laser action was also achieved, for what we believe is the first time in Nd:GGG, on the quasi-three-level 937-nm transition. With a 2% output coupler at this wavelength a laser threshold of 17 mW and a 20% slope efficiency were obtained. This demonstration of low propagation loss combined with the fact that these waveguides have a very high numerical aperture (0.75) makes pulsed-laser-deposited thin films attractive for high-power diode-pumped devices. (C) 1997 Optical Society of America.