Antything beyond 800 nm is essentially invisible to the <human> eye. the laser in this case is 10,000 nm wavelength. If I were to go with a "killer" laser I would choose an Nd:Yag system....but the YAG system I used last required support equipment that would pack a Semi truck trailor ... and even then I just worried about being blinded or losing a finger that was 1500 watts, (btw never had an accident) Laser weapons are never going to be like the star wars movies <ie bolts of light you see flying through the air>

an addendum: I know lasers, but have not worked on laser weapons- so I am not in the know on what killer systems are being developed....i can only guesstimate- I do know we have hand held systems that can burn and blind....but as hand held systems go that is about it....