Maybe better; how long/how many sessions do you want these to last and how mobile do you think your combatants are going to be? That's where my concerns come from. That, and the sensitivity aspect.
Ah, I suspected that this is where we would go at some point. Being able to see the beam is not a function of power per se. It's a property of the atmosphere. For the beam to be visible you need scatter as a result of atmospheric pollution/particles. Think smoke or vapor. So if you want this, you'll need to fog the whole area just enough so the beam is visible, but not so much that it comes at the cost of a significant amount of power (after all, all scattered light nicely shows the beam, but cannot detected anymore by your sensor!) That's going to be a balancing act, and I doubt it'll be feasible to begin with - perhaps in an indoor setting, but even there it will be tricky.