Re: Pretty feeble compared with Phalanx @Credas (Agreed with caveats)
Credas, You would be correct, the best COTS solution is a chaingun.
However the US Navy is also looking at Rail Guns to replace Phalanx, but the laser could have some capabilities against incoming anti-ship missles as they often present themselves head-on and the speed of light is kind of hard to beat.
All they need to do is fry the electronics in the guidance section to bring it down.
Whose to say you could not have multiple weapons sharing the same radar?
As far as penetrating projectiles go, those from a rail gun would be much faster than those from a chaingun. It does take longer to "charge" the weapon but have you ever seen what one can do? The projectile goes 5,000 miles per hour and ranges approaching 100 miles. (and 32 megajoules of energy at the muzzle) That's like being hit with an asteroid, not much can stop it.
Look for the video link at the bottom of this web page
BTW, mirrors or light guides as anti-laser "armour" are often ineffective. The "Star Wars" program from the Reagan era used spinning mirrors as part of the space based laser itself. They spun to increase wear life but had to be replaced very often as the first surface mirror material would vaporize after a few shots.
This newer shipboard laser is solid state and is further described in this link:
In order to do any real damage the ground based laser would have to emit infrared energy (think CO2 Laser) which would melt anything like a mirror in a few seconds or less without even having tar on it.