Power scaling from buried depressed-cladding waveguides realized in Nd:YVO4 by femtosecond-laser beam writing

We report on output power performances obtained by diode-laser pumping of buried cladding-waveguides that were inscribed with a femtosecond-laser beam writing technique in several Nd:YVO4 media. Continuous-wave output power of 3.4 W at 1.06 µm for an absorbed pump power at 808 nm of 10.3 W was obtained from a circular waveguide of 100-μm diameter that was realized in a 6.9-mm long, 0.5-at% Nd:YVO4 crystal; the slope efficiency with respect to the absorbed pump power was 0.36. The pump at 880 nm, directly into the 4F3/2 emitting level, was used to improve the waveguide output characteristics. With an absorbed pump power of 9.8 W at 880 nm, the same waveguide yielded 4.4 W at 1.06 µm, whereas for emission at 1.34 µm the output power reached 1.7 W; the slope efficiency improved to 0.47 for laser emission at 1.06 µm and reached 0.24 for operation at 1.34 µm. Results recorded from similar waveguides that were inscribed in 0.7-at% Nd:YVO4 and 1.0-at% Nd:YVO4 crystals are presented.