Efficient Ti:LiNbO_3 ridge waveguide lasers: Investigation of Er and Yb:Er doped waveguides pumped at 980 nm and 1486 nm

摘要

Erbium-ytterbium-codoped titanium in-diffused ridge waveguides optical amplifiers in x-cut congruent LiNbO_3 substrates pumped at 980.5 nm and 1486nm are reported for the first time. An internal gain of 2.8 dB/cm has been measured in 2.3 cm long Yb:Er:Ti:LiNbO_3 ridge waveguides for the coupled pump power of 145 mW at 980.5 nm, which is the highest gain ever reported, to the best of our knowledge, for erbium-based LiNbO_3 waveguide amplifiers under 980 nm excitation. Furthermore, we realized an internal gain of 3.2 dB/cm for the coupled pump power of 200 mW at 1486 nm, which also exceeds the best literature values for Er:Ti:LiNbO_3 waveguide amplifiers pumped at this wavelength. In addition, we report on a method for local periodic poling (periods of 30 μm and 18.4 μm) of ridge waveguides in LiNbO_3, which allows for future integration of waveguide lasers and nonlinear frequency converters on the same substrate.