Mode selection processes are presented for a 200 µm active thickness Nd:YAG planar waveguide laser, pumped by 10 laser diode bars in a multi-pass, slotted mirror pump chamber. A hybrid waveguide-unstable resonator is shown to be effective at mode control, producing a single, edge-coupled output beam of up to 5 W average power for quasi-CW pulsed pumping. A lateral M2 factor of 1.5 and a low order waveguide mode with a transverse M2 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. © 2001 Elsevier Science B.V.
- Planar waveguide laser