I have just realized that when the door is open people can look into the laser transmitter. How powerful is it, and is this dangerous? Should I mount the reflector on an extension at the top of the door so that the laser fires above the opening?
The laser is 5mW which is the type used in laser pointers, but the pulse is very short so there is no long exposure. Even without danger to the sight it may be unpleasant if the laser is pointed at the eyes. If you encounter this situation, consider changing the angle or pointing it at the wall immediately above the door so the door blocks the reflector when it starts opening.