A planar waveguide Nd : YAG laser with a hybrid waveguide-unstable resonator

Mode selection processes are presented for a 200 mum active thickness Nd:YA G planar waveguide laser, pumped by 10 laser diode bars in a multi-pass, sl otted mirror pump chamber. A hybrid waveguide-unstable resonator is shown t o be effective at mode control, producing a single, edge-coupled output bea m of up to 5 W average power for quasi-CW pulsed pumping. A lateral M-2 fac tor of 1.5 and a low order waveguide mode with a transverse M-2 factor of 4 .3 is obtained with 4 W output. The resonator configuration is shown to be unaffected by transverse or lateral thermal lens effects. (C) 2001 Elsevier Science B.V. All rights reserved.