It's not just my wish list, such coatings actually exist to deter laser targeting. The only unknown is their efficacy against a high powered energy weapon. And since they work on passive cancellation, they will be effective no matter how much time elapses.
High powered lasers are also subject to attenuation in the atmosphere, especially in severe weather.
One area where they could work very well is space - if the power problem could be solved.
Hi, you can not compare the coatings used for deterring target tracking and protective measures against laser weapons. Although I'm not an expert in military uses as such but I know a thing or two about optics in specific and physics in general... Let me try and speculate a little:
1) Target designation Lasers:
purpose: to identify a target so that friendly forces can take it out or avoid it or whatever the tactical use...
The basic operation would be that a laser beam is projected onto the target which
reflects it and friendlies see that reflection, lock on the weapons to that and do what they need to.
Countermeasure: If you're someone trying to prevent your enemy from using laser designation against you, you'd try to minimize the intensity of the reflected laser beam. To do this you'll use coatings that
absorb the laser energy projected your way, minimizing reflection so that tracking the reflected 'spot' is difficult.
Now any energy 'absorbed' needs to be dissipated, that's not a problem with the hypothetical laser absorbing coatings discussed above since the target designation lasers are not very high in intensity, as compared with the ones we're going to talk about below. So, most probably the energy of the absorbed photons becomes thermal energy and is dissipated as such.
2) Laser Energy Weapons:
Purpose: to destroy a target by projected very high-intensity laser on to a known target. The mechanism of action will be to exploit precisely what was the savior in the scenario above. All materials absorb some part of the incident laser's energy. The very high power laser would fall on the target and part of it will be absorbed, now if the material cannot dissipate that absorbed energy quickly enough, the temperature will start to rise. The goal of the weapon is to deliver enough energy quickly enough to either destroy the target thermally or at-least deliver enough energy to destroy/disable (fry) some vulnerable critical systems such as electronics.
So you see a coating designed to beat laser designation could potentially make matters worse when a high-intensity laser is projected onto it as a weapon.
note: I'm not saying countermeasures cannot be built, just saying an absorptive coating would make matters worse.