The JSF laser is a solid state laser that will be able to fire a distance of ~6 miles. The current prototype has a power of 13 Kw with the final production model having a power output of 100Kw. The Laser will be able to fire two four second bursts four seconds apart and then have to cool for roughly 30 seconds before it is able to fire again.
The penetration power of a 100Kw beam is also not great, certainly it is conceived as a weapon against very soft targets and as a defensive measure.
I believe this is one of the reasons that the USAF
is considering a F-35B purchase as it will be easily modified to allow for the laser attachment, since it will have the shaft connected straight to the engine. A 100Kw laser will require at least 1 megawatt of input power and will require serious cooling, so much that the current plan is to pipe the heat through the fuel tank considering the amount of fuel carried on aircraft. This should also only raise the temperature of the fuel tank by a degree or two and enable the stealth to be maintained.
An excellent idea although I am a bit sceptical that they will reach the expected power output level of 100kw anytime before 2015.
As far as a space weapon system is concerned, DfwRevolution is right, sunlight alone is simply not strong enough the penetrate the atmosphere due to refraction. This is why Lasers are tried instead as all the photons in the beam are oriented in the same direction or coherent, the beam having very little divergence over the length of the path, something like 1mm per meter traveled for typical laser designators.
There is a Space based laser concept that continues to attract funding by the US, a large weapon with a power of 5-10 megawatts and a range of 4000K outside atmosphere but would only be able to penetrate a distance to about 3000 meters above sea level before dispersal and interference negated it's effect. It would also weigh about 35 tons (three time Hubble) and hence cost a fortune is place in orbit, let alone the over a billion in construction costs each and require at least twelve to give any sort of coverage.
It really comes down to cost and until a viable interorbit vehicle that can bring costs down is created we will never see very large mirrors or lasers in orbit.