High-efficiency longitudinally-pumped miniature Nd : YVO4 laser

We report on fundamental and intracavity frequency-doubled emission in a mi niature Nd:YVO4 (3 x 3 x 1 mm) laser. A maximum slope efficiency of eta(s) = 58.6%, with optical efficiency of eta(0) = 53.0% at 780 mW pump power was realized in a TEM00 output beam. To obtain the optimum pump-beam focusing conditions we applied a new formalism in which the pump-beam propagation in the active medium was described by its M-2 factor. A good agreement betwee n theoretical predictions and experimental results was observed. In second- harmonic regime, obtained by a KTP crystal, similar to 230 mW green power t hat corresponds to similar to 54% nonlinear conversion efficiency was reach ed. (C) 1998 Elsevier Science Ltd. All rights reserved.