Happiness Is A Warm Gun
Member
Popular Science ran an article about weapons of the future way back in june or july of 2004. One of the questions was wether lasers could be deflected by mirrors or not. I thought to myself "What a silly question, or course not! I was right, although a mirror reflects light energy it can do nothing about heat energy directed at it. All a mirror is is a piece of polished metal behind a sheet of glass. It would simply melt/explode depending on the energy of the laser.
That is not exactly true. Lasers have no heat. They simply emit light. When the light strikes something it produces heat. The reason why mirrors or any object struck with high energy laser get hot is no mirror is perfect.
The mirror in your house reflects only about 90% of light that hits it. The other 10% is converted into heat due to imperfections in the mirrior. So if you shot your house mirror with a 10w laser it would convert 1w into heat and raise temp of mirror.
The problem with military lasers it is fairly easy to raise the reflective index of the target "enough" to make the laser ineffective.
Take the ABL (airborne laser). It is designed to shoot down enemy short range and medium range tactical missiles. It features a megawatt laser as the kill laser. The laser is so massive it takes up a 747 and requires a chemical reaction to produce the energy needed. Despite that and it's advanced targeting and beam shaping system it only has a range of 300-600km.
That is without countermeasures. A missile is not very reflective (converts most light to heat). Take the same missile and shine it to a mirrored shine and it may take 2x the energy to burn a hole in the skin and destroy it. Want even more protection, have missile dispense and IR opaque gas. With a gas that blocks out 75%-80% of lasers energy it would take 4x-5x more energy. Want even more protection. Rotate the missile. Now instead of burning a single point in the missile you are burning a band around the missile. That will take about 3x more energy. Now if you put all these counter measures together you can quickly require an astranomical amount of energy (more than the ABL) can provide. What can the laser do to overcome it.
1) shorter range results in more energy to target.
2) larger laser (except the ABL already takes up a 747)
3) multiple lasers (except the single ABL has costs billions to develop and is vulnerable to being shot down).
So $$$ is on the side of the defender. Each $ the defender spends make take $20-$30 to overcome.
Militarized Lasers are a dead end in all but a limited niche applications. Even in those applications they may not be useful.