PERFORMANCE OF A LOW-LOSS PULSED-LASER DEPOSITED ND-GD3GA5O12 WAVE-GUIDE LASER AT 1.06-MU-M AND 0.94-MU-M

We report the laser performance of a low-propagation-loss neodymium-do ped Gd3Ga5O12 (Nd:GGG) waveguide fabricated by pulsed-laser deposition . An 8-mu m-thick crystalline Nd:GGG film grown upon an undoped Y3Al5O 12 substrate lases at 1.060 and 1.062 mu m when pumped by a Ti:sapphir e laser operating at 740 or 808 nm. Using a 2.2% output coupler, we ob served 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 tim e in Nd:GGG, on the quasi-three-level 937-nm transition. With a 2% out put coupler at this wavelength a laser threshold of 17 mW and a 20% sl ope efficiency were obtained. This demonstration of low propagation lo ss combined with the fact that these waveguides have a very high numer ical aperture (0.75) makes pulsed-laser-deposited thin films attractiv e for high-power diode-pumped devices. (C) 1997 Optical Society of Ame rica.