Fabrication parameter optimization of a low-threshold high-efficiency proton-exchanged waveguide laser in Nd:LiTaO(3).

Knowing the correlation between the Nd(3+) excited-state lifetime in proton-exchanged waveguides and the phase diagram of the H(x)Li(1-x)TaO(3) compound permits optimized waveguide fabrication parameters to be found. These have been used to produce a Nd:LiTaO(3) waveguide laser with a threshold of 2.9 mW and a slope efficiency of 33%, in good agreement with the best predicted values. Nevertheless this component suffers from instabilities because of the photorefractive effect.

Quasi-phase-matched parametric fluorescence in room-temperature lithium tantalate waveguides.

We report what is to our knowledge the f irst observation of quasi-phase-matched parametric fluorescence in the 1.2-2.3-microm region, at ambient temperature, in lithium tantalate waveguides, using a pump wavelength between 805 and 845 nm. The signal fluorescent power depends strongly on the proton concentration in the waveguide, and signals of up to 7 pW have been observed for guided pump powers of 70 mW, which is 1 order of magnitude lower than the efficiency measured with lithium niobate guides.