(check link for idea)
You need the refractor (I believe is the term) to stop the laser from continuing on forever until it ultimately dissipates. (It is a very rough 2 min sketch)
A laser like this would require a lot of power.
PS: color depends on the laser type and power.
PPS: it is cool if you ever look up the U.S. military uses laser equipped jets as anti missile aircraft. (as previously stated)
PPPS' Many metal working company's use lasers to precision cut components. One local to me is Mayville Engineering Company.
PPPPS: Do you guys think a plasma saber would be cool. If so any ideas as to if its possible. I wonder? That question gets me in trouble a lot.