They sell direct fit, diode laser modules for them. I'll probably get whatever the hottest one I can get for these is. Looks like 10w optical output multi diode is about the biggest ready made option, but I'm skeptical and the lack of enclosure and ventilation or any kind of fire abatement is a little off-putting.
Fuzzydog I'm going to do a little engraving for some charity work, fundraiser. That's the primary reason I bought it. Also I like to tinker on things and design stuff in CAD. 3D printed parts aren't always up the task. This gives me a whole new method and countless new materials to get overwhelmed and frustrated with.