Interesting reading:

http://news.usni.org/2016/03/28/document...port#more-18766

SSL (Solid State Laser):

Now thinking about ~ 200kW power used within a few km of protection instead of the previous "MW" level, and hundreds of kilometers ranged powerful lasers.
No mention of the Free Electron Laser from which a few years ago was proclaimed a large world-saving technology.
Currently, the most important technological problems:
-The Current laser technologies has only ~30% efficiency, a significant move forward from here is difficult (ie: with an optical 200kW performance laser, you need to get rid of circa 460kW thermal heat).
-The providing optical 'window' purity of the salt water, and dirt.
-The problem of atmospheric factors (humidity, fog, rain) at greater distances

EMRG (Electro Magnetic Rail Gun):
Current technical problems:
- Barrel life
- Upgrade current 8MJ muzzle energy to 32MJ
- Dissipating barrel heating during 10 rounds/minute rate of fire
- Size And weight requirement for existing ships (~ 600 tons per moments of a 32MJ EMRG gun, in Burke only 60 tons available)