Efficient ridge waveguide amplifiers and lasers in Er-doped lithium niobate by optical grade dicing and three-side Er and Ti in-diffusion

Highly efficient erbium-doped titanium in-diffused ridge waveguide optical amplifiers and lasers in x-cut congruent LiNbO3 pumped at 1486 nm have been developed. A total internal gain of 14 dB has been achieved in 4.6 cm-long waveguides for a coupled pump power of 200 mW. We demonstrated a laser operating at 1561 nm with a slope efficiency of 33% exceeding the best literature values for Er:Ti:LiNbO3 waveguide lasers. To improve the amplifier/laser performance, our novel fabrication technique of three-side Er and Ti in-diffusion into pre-defined ridges was used.