Laser engraving picture on wood with 2W laser diode

Laser is mounted on a Prusa i3 style 3D printer.
Laser components purchased from odidforce.com:
- 1.6W (@2.0W) NDB7775 (OFL150-1)
- 2A Laser Diode Driver (OFL121)
- High Efficiency Mounted Collimating Glass Lens (OFL3)
- Heavy Duty Heatsink Module (OFL449)
Great online software for image engraving:
- http://www.thingiverse.com/thing:770081