Okay, I’m not a laser physicist, but I have read a few articles.
Any errors I mention here are likely flaws of my recollection of said articles. Be warned.
First off, the laser weapon has one huge problem, and that is the fact that a great deal of it’s energy is lost to the air. Even on a clear, calm day, megawatts of the laser’s output is simply heating up the air in it’s path, basically boring a hole in the atmosphere itself.
The heated air roils and throws the laser off target, just as the air will shimmer a little on a hot day. When the range-to-target is measured in miles, even a tiny error caused by the motion of the superheated air can mean a miss.
As I understand it, the real problem is less mere raw power, it’s getting that power to the target. The “cure”, so to speak, is massive computer power linked to super-accurate radars, which in turn run “adaptive” optics- meaning a deformable aiming mirror, which does the actual aiming of the beam.
The heating problem, even with the advanced optics, becomes even more of a problem when the target is travelling at a high rate of speed. The laser then has to keep cutting a new path through the air as it tracks.
As for defenses, a high-power laser weapon will have little or no “dwell” time- the incoming beam literally strikes like a cannon shell, producing something more like an impact effect rather than a “burning” or “melting” effect.
A polished surface may actually attenuate the effects to a tiny fraction of a degree, but by no means will a potential target be astronomical-mirror-quality polished. And in any case, from what I’ve read, the surface finish is more or less irrelevant, since, as I mentioned, the high-energy photos strike with something like an impact force, not a “heat” effect.
The same goes for ablative armor or “liquid” shielding- which I haven’t heard of. For something like a ballistic missile, even the near-explosive destruction of a layer of ablative armor will very likely damage the missile itself.
And as mentioned, the weight of the armor itself might cut the range of the missile down by a significant margin.
As for targeting, in an infantry situation- say a laser-tank 200 yards away, the “beam” cannot be “dodged”. But then, the same can be said for a bullet too. The bullet may take milliseconds, while the beam may take fractions of a microsecond, but in either case, it travels about three orders of magnitude faster than human reflexes.
However, targets move, it takes time for weapons to function, and it takes even more time for an operator to actually fire it.
For example, it might take several milliseconds for the gunner to recognize the target, possibly most of a full second to align the sights- if he’s fast- and a few more milliseconds to tell his trigger finger to pull the trigger.
Then in a mechanical gun, there’s a few more milliseconds for the firing mechanism to ignite the primer, and depending on the range to target, a sizeable fraction of a second (or even several whole seconds) for the projectile to actually traverse the distance.
With a laser weapon- which we’ll assume near-instantaneous discharge when fired- the speed of the “projectile” may well be faster, but the human reaction times (to fire the thing) and the time needed to actually aim the bloody thing, will not be all that much different.
And when one considers a ground-based (or even airborne) laser many miles from the target, which is travelling at what, several thousand miles an hour? Then even the fractions of a microsecond it takes for the beam to traverse the distance can still mean a miss.
Anyway, to answer the original post, it’s my opinion that laser and “particle beam” weapons (lasers are, after all, simply beams of concentrated, energized pparticles called photons) when properly developed and aimed, will definitely be part of future weaponry.
The effectiveness will depend on how portable a powerful laser can be made, how accurate the aiming system- whether it’s a dot-sight for a trooper or a radar array for an ABM system- and how fragile it all will be.
Simply due to the fact that even with ultra-miniaturization of the circuitry, and advanced developments on electronic efficiency, I doubt the individual soldier will ever have a laser-rifle to replace the M-16. But for something like an Aegis cruiser anti-missile defense, or a replacement for the CWIS/Phalanx anti-missile system, very possible indeed. Given a compact enough bank of capacitors, even tanks and Bradleys could have effective lasers… eventually.
