Er-Thermally-Diffused Ti:LiNbO3 Waveguide Laser.

Abstract

An Er-thermally-diffused Ti: LiNbO3 waveguide laser was demonstrated. Er diffusion into LiNbO3 was a key process to implement the waveguide laser, and we found that thermal diffusion of an Er film of13-nm thickness at 1090°C for 100 h in dry oxygen atmosphere provides Er-diffused crystal with a smoothsurface and appropriate Er concentration. A waveguide laser was fabricated using the crystal. The waveguide laser cavity consisted of a Ti-diffused channel waveguide with 10-μm width, a dielectric mirror attached on one waveguide facet and an Au mirror deposited on the other facet. The laser was optically-pumped at 1.48-μm wavelength, and CW laser oscillation was obtained at 1.53 μm with a threshold of 10 mW. A maximum laser output up to 100 μW was obtained so far.