OT: Navy's new laser weapon

That old thing?

Try the new stuff - a free-electron laser

It's still in the pop-gun class at only 14 KW.

But the potential is defiantly there.

Excite certain kinds of atoms, and light particles ? photons ? radiate out. Reflect that light back into the excited atoms, and more photons appear. But unlike a light bulb, which glows in every direction, this second batch of photons travels only in one direction, and in a single color, or wavelength. Which slice of the spectrum depends on the ?gain medium? ? the type of atoms ? you use to generate the beam. But the free-electron laser is unique: It doesn?t use a medium, just supercharged electrons run through a racetrack of superconductors and magnets ? an accelerator, to be technical ? until it produces a beam that can operate on multiple wavelengths.

'Looks good, but the first one is almost ready to roll. Next year, they say, they'll be able to deploy them.

I really like the $1/shot part. d8-)

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I do to, but I don't believe it. Maybe per pulse.

But it tales a lot of pulses to melt steel.

The faster you do it, the more power it takes.

If it's $1,000/shot, that's still one hell of a cheap weapon for that job. Compare that with a surface-to-air missile. Ouch.

Very true.

And if it works (I mean REALLY works) the surface fleets will be back in the game.

Right now the best toy in the box for close-in supression is the aging Plalanx.

But even the new laser is still line of sight. Until it gets airborne, it's a close-in hole card.

So does the Navy! (or the media?) They are really pushing that buck a pop thing.

I'm wondering what the pulse repetition rate is on this thing.

1 megahertz? $1 a shot would be $1,000,000 a second at that rate. :)

No tech specs available anywhere yet. No surprise.

Yes. And the bigger advantage is that one need not store rounds (explosive, and take up space), and cannot run out of bullets.

But I would mention that this deployment is probably more to gain field experience than anything else. Nonetheless, this is the future.

Joe Gwinn

the post was

the navy shot down a 3 foot balsa model/kite flying at 20 miles per hour?

that's sure as hell what it looks like.

High power lasers are not so new really.. There have been systems capable of shooting down (really, heating until destruction) artillery shells, mortar rounds and rockets/missiles.. Like Israeli THEL from 2000..

It is most propably a chemical laser, where a population inversion is made with a chemical reaction in the resonator. Some very nasty chemicals involved..

There will be LOTS of blind people after using such a weapon. :/

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Well... there's the "fixed cost" -- a mere $32,000,000 -- to consider. If it turns out that the laser only gets off 32 shots before it self-destructs or otherwise becomes unusable, that's an amortized(?) $1,000,000 per shot.

But I like it, too.

Frank McKenney

It will be just part of the future. Any laser will be severely affected by clouds and rain. It is also easy to partially defend against by coating things with high reflectance materials. Such a coating means the laser has to sit on target more than 10X longer at a given range. Still, it can do things no other weapon can, so it will be another useful weapon in the arsenal.

There are some wavelengths that travel through water vapor better than others, but there is still pretty significant attenuation. In theory a laser can burn its own hole through clouds and rain, but this takes an awful lot of power.

As for the $1 per shot, they said "extended pulse", and they certainly implied that would be enough to blind or kill a drone. They apparently are simply using commercial fiber lasers. These usually have very little maintenance, but there is the cost of the $32 million system divided by the number of times it will ever be shot.

We can count ourselves fortunate that any enemy will never have heard of corner reflectors.

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And it is also fortunate that laser physicists are not stupid. In order to reflect the beam with the same divergence, the corner cube reflector would have to be at least twice the diameter of the orignal telescope launching the beam. If the telescope was 10 inches, the corner cube would have to be

20 inches wide and about 10 deep. Not very aerodynamic. If you just covered the target with small retroreflectors, the divergence increases in inverse proportion to the reflector size, and returning intensity falls off as the square of the divergence.

Still, it is possible to mount such large reflectors on ships or larger airplanes (which are not really the primary targets of this laser anyway). But I would guess that the laser has a sensor to detect when back reflections become dangerous to shut it down. This would be needed not only for such reflectors, but for cases when something happens to accidently be immediately in front of the laser, or if there is bird poop and such on the lens.

Any reflector will make it more difficult for the laser to do its work, but it is very hard to make a reflector sitting in the environment that will withstand a high power laser for very long. Any little speck of dirt or defect absorbs energy creating a bigger defect, and the process then cascades very quickly.

if anybody watches that video, it's clear that you only need to fear that laser if you're a 3 foot balsa model or kite flying at 20 miles per hour.

Yes, those target drones are pretty flimsy, although any enemy drone probably would be as well. But I think what this video really showed was the targeting system used to identify the position of the camera on the drone (all cameras reflect back some of the signal), and then the capability to blind a surveillance camera. I am sure that this is the real mission of this particular laser (blinding an Iranian drone is much less provocative then shooting it down). The images of burning planes are mainly for publicity, funding, and giving a taste of future capability. Still, if you want to shoot down a drone, this gives an option other than a missile that is more expensive than the drone.

Eventually these lasers will be much more powerful.

I'm pretty sure that this is intended for close-in defense, when the ship is being swarmed and the ranges are short, short enough to simply burn through the rain and fog.

I have no idea how the cost was computed, but the cost comparison is with existing military systems of similar capability, and such things are often dominated by logistics.

Joe Gwinn