[RadioAstronomer]

Pity he didnt say what color, as that would narrow it down a bit.

I was wondering the same thing. If it was green, it could have been an Argon Ion or a dye laser. If it was blue, it may have been a krypton. Red could be lots of stuff. Obviously, IR (CO₂) are ruled out.

[AdamSelene235]

was wondering the same thing. If it was green, it could have been an Argon Ion or a dye laser. If it was blue, it may have been a krypton. Red could be lots of stuff.

Argon Ion would do it as would doubled YAG (really nasty).

Obviously, IR (CO2) are ruled out.

I've actually experienced 1064 nm as a color, but this occurs at very dangerous retinal intensities where nonlinear processes start kicking in.