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DOD working on 100kW battery powered laser

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Steve Conner

Thu Mar 01 2007, 12:34PM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

I don't know if you guys have seen this before but I thought it was pretty impressive:

Lawrence Livermore are working on a 100kW diode-pumped Nd:YAG laser that runs off lithium-ion batteries and can be mounted on a Humvee. They have got their prototype up to 67kW and are blowing holes in all sorts of metal with it.

Sulaiman

Thu Mar 01 2007, 02:51PM

Registered Member #162 Joined: Mon Feb 13 2006, 10:25AM
Location: United Kingdom
Posts: 3141

Makes my 5 mW HeNe look a bit boring

An interesting idea ?
What would happen if targets were coated in "cat's eyes" or miniature 'corner reflectors'?

...

Thu Mar 01 2007, 04:08PM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

really, when you think about it, a self contained 100kw laser is pretty impressive. nd:yag can be 50% eficient if you are lucky, so you need 200kw of diode pump. The diodes are 50% eficient, so you need 400kw of electrical power, and a way to cool that 500kw load...

Marko

Thu Mar 01 2007, 08:03PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

Hi steve

There's a vid featuring MTHEL shooting down some rockets, mortars and artillery shells:

Electrical laser of such power is nice but I imagine very costly considering all this, without some special advantage over chemical lasers.

From other side, this is my favourite laser destruction machina

Steve Conner

Fri Mar 02 2007, 11:24AM

Registered Member #30 Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706

Heh, I thought you would appreciate that ... since I heard you're trying to build your own diode pumped Nd:YAG. They use a crazy pump diode array that has the diodes mounted on silicon microbenches with water cooling channels micromachined into them. The prototype of that puts out 41kW of pump light from an area about the size of a cassette tape.

Firkragg, the MTHEL movie is pretty awesome

That beam director thing should be labelled "Do not look into beam with remaining blazing head stump"

It's neat how you can see the hot chemical laser "exhaust" blasting out the side of the thing in the false colour IR shots of the area. A chemical laser is more or less a rocket engine with really exotic fuel and an optical resonator bolted onto the nozzle.

Marko

Tue Mar 06 2007, 09:20PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

Hi steve

Firkragg, the MTHEL movie is pretty awesome That beam director thing should be labelled "Do not look into beam with remaining blazing head stump"

Yup, I'm actually most amazed by it's ability to lock on quickly on high-speed prjectiles.

Beam director is small and agile compared to bigger lasers like MIRACL, wich seemingly compensate this by their bigger range.

Note how beam is wide as it leaves the director (visible in IR).. not something even close to even ''realistic'' holywood interpretations (I hate television

) It seems to focus the beam only at it's target; if beam was made as narrow as possible in entire length it would probably suffer heavy blooming and losses. Not to mention that laser is invisible IR because it's simply easier to make powerful and efficient laser in that wavelengths.

Ben

Thu Mar 29 2007, 08:50PM

Vigilatny
Registered Member #17 Joined: Thu Feb 02 2006, 02:47PM
Location: NL
Posts: 158

I don't think the exhaust from those chemical lasers is too healthy/pleasant. Probably a little better than shrapnel though.

That 100 kw laser was proposed about 3 years ago. Anyhow electrically powered lasers are attractive because they only require electricity, which can be made on demand in a variety of ways, unlike deuterium fluoride, etc.

...

Fri Mar 30 2007, 02:24AM

Registered Member #56 Joined: Thu Feb 09 2006, 05:02AM
Location: Southern Califorina, USA
Posts: 2445

yes, solid state lasers are greatly prefer ed over chemical lasers because a chemical laser requires a fill of some pretty nasty chemicals (and probably a new set of optics, alignment, good cleaning, etc) between shots compared to a yag laser that will laser that is ready to go at all times, just give it electricity.

Also, the wide beam is more advantageous that you might think, due to the nature of laser beams. Due to nature of light even an ideal beam with a small initial width (say 1mm) would have a solid 1mrad of divergence, so at a mile away the beam would be over a meter in diameter, and the power density would be .5 millionths of what is started out

But now that I have been trying to get some lens alignment done, I am extremely amazed at the tracking ability that thing has... Think about it, if it can keep the spot within 1" at a mile away that is .01mrad ( .001 degree), and it can move like a full rad (180deg) in under a second!

Marko

Tue Apr 03 2007, 01:08PM

Registered Member #89 Joined: Thu Feb 09 2006, 02:40PM
Location: Zadar, Croatia
Posts: 3145

Also, the wide beam is more advantageous that you might think, due to the nature of laser beams. Due to nature of light even an ideal beam with a small initial width (say 1mm) would have a solid 1mrad of divergence, so at a mile away the beam would be over a meter in diameter, and the power density would be .5 millionths of what is started out

Yes, and ot only the focusing problem, but I can imagine what immense blooming would occur over entire length if 100kW was dumped into few square milimeters of air.

Keeping beam as wide as possible at director and focusing it just at the target is generally better thing, as much as weight/inertia of the beam director doesn't start to burden it's tracking ability.

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