Abstract

Titanium may be diffused into sapphire for the fabrication of waveguides and waveguide lasers.^1,2 However, the low index elevation of titanium-diffused waveguides at Ti concentrations appropriate for lasing results in large modal spot- sizes and high pump power thresholds. The use of two different ions independently to control the characteristics of the waveguide and of the gain medium leads to greater design flexibility.^3–5 Previously we demonstrated that gallium may be diffused into sapphire to create planar optical waveguides with index change of 6 × 10⁻³.⁶ It is expected that titanium and gallium may be combined in sapphire, as the active and waveguide ion respectively, leading to the fabrication of low- threshold broadly tunable waveguide lasers. In this paper the realization of gallium-diffused channel ridge waveguides in sapphire is reported.

© 2002 Optical Society of America