Do you really need to burn through steel plate? Seems like something like this is for shooting down cheap drones.
Though I've always wondered about laser weapons -- I'd think the obvious defense is cladding the device in a mirror surface.
A mirror will not work. At the power levels involved, any mirrors must be precisely tuned to the exact wavelength of the laser (e.g. dielectric mirrors) and they must be immaculately clean. That level of cleanliness is impractical in a military environment. Furthermore, the US has developed "white" laser weapons, which will defeat any tuned dielectric mirror like it wasn't there since the lasers have a broad spectrum of wavelengths.
There are fundamental limits to material physics. Spinning doesn't help because there are always fixed points by definition. There are both materials science and engineering limits to spin rates, so you can precisely design your laser power levels to be reliably effective at the upper bound spin rates. All of this was fully modeled out and calculated half a century ago. Other countermeasures, like dielectric mirrors, would be very expensive to use on cheap weapons, and the US already developed a counter-countermeasure anyway with the invention of lasers that emit "white" light.
The scientists and engineers that did R&D on this over the last several decades weren't idiots. Everything "obvious" that armchair weapons experts might come up with were accounted for a long time ago.
That alone would be a major capability for a layered defense system. Cleaning up decoys would be another one (not necessarily getting those down, IDing them due to reflectivity is almost as good).
1. Russia had its own DEW system since at least 2018, and doesn’t currently use it on or off the battlefield
2. Israel has Iron Beam, reportedly a 100KW DEW system, and also doesn’t use it
Perhaps it’s not as cool as it says on the tin?
A common misconception
If you want a fun read, the Galileo probe wall ablation paper is fun, the re-entry power density (at the wall!) was ~10kW/cm^2.
Rotation dramatically increases effective armor thickness if energy is delivered over a long time frame etc. But drop to the nanosecond range and a cloud of plasma which used to be the armor is going to between the laser and what’s left of the armor. That said, you don’t need to drill through a target, a jet of ablated material means an equal and opposite force is going in the other direction.
Really though the biggest limitation of a laser defense system is pure kinetic kill weapons. Big thing moving Mach 2+ is deadly even without pinpoint accuracy or being filled with high explosives.
Intumescent paints are considered the lightest form of passive fire protection. An intumescent is a coating that, when exposed to heat, is rapidly transformed through sublimation, and expands many times its original thickness (up to 100 times), to form a stable, carbonaceous char.
The resultant char reduces the conduction of heat from the fire to the substrate, delaying the time it takes to reach structural failure.
I'm considering getting some for my kitchen remodel.
https://www.nullifire.com/en-gb/expert-insights/expert-advic...
not if you're accurate enough to hit its sensors
It's possible to have a pre-programmed map, objective destination and accelerometers to judge distance.
those things usually have some sort of heat/EM/something seeking sensor to make it accurate to the last meter, and those still can't "see" through metal (yet (that we know about))