How to power and switch a laser diode?
I would second the safety aspect. Lasers are not toys. There is a departmental story that a student a few years ahead of us permanently lost vision in both eyes because he happened to walk into a lab whose laser was on. The laser wasn't even pointed at him, just him glancing at the reflected light was enough to cause serious eye damage (the eye does get drawn naturally to bright spots). 

An important principle in laser safety is that you can control variables associated with where the beam is pointed, that it is enclosed and that you can control access while the beam is on. A robot moving around with a non-eye safe laser sounds like a recipe for trouble, unless you can control all the above variables, such as doing the tests in a locked room.