Yikes:
Trying to come up with a practical application of that. The best I’ve got is as a weapon. Not to set things on fire, but to blind optics and enemy combatants. Imagine turning that on and sweeping it across an attacking force of Taliban; it would cause them to duck for cover perhaps even more effectively than a machine gun. Of course the soldier using it would have to wear a helmet that completely covers his eyes; I’m think that the best approach wouldn’t be lenses that selectively block the laser wavelength, but a mask that completely cut the eyes off from the outside world and replaces it with augmented reality vision. Anybody fighting alongside this laser weapon would have to be similarly equipped.
Of course it’s so bright that the air itself lights up via Rayleigh scattering, so it would serve as a dandy “here I am, shoot at me!” beacon.