Scientists invent the Superlaser

[Modax]

link

Science fiction fans and generals alike have long fantasized about what it'd be like to have a laser weapon at their command. Now at last such dreams are nearing reality. After years of steady milestone progress, military contractor Northrop Grumman has reached a significant mark -- the first 100 kW steady-state laser.

The laser is part of the Joint High-Powered Solid State Laser Phase 3 Program, which combines 8 lasers in chain fashion to create a "superlaser" of sorts. Each laser can deliver up to 15.3 kW individually and is about the size of a large briefcase. Together they form a unit about the size of a couple garbage dumpsters stacked together, which can deliver a peak beam of 105.5 kW. The device has operated continuously for 5 minutes, a major landmark in integrity.

The beam quality is an impressive 3.0 or better, and full power is reached in 0.6 seconds.

At 100 kW, the laser is capable of delivering a military-ready deadly beam. The unit could see deployment aboard next-generation battleships and cruisers or aboard large aircraft. States a company release, "In fact, many militarily useful effects can be achieved by laser weapons of 25 kW or 50 kW, provided this energy is transmitted with good beam quality, as our system does."

However, the relatively large weight and high power requirements remain obstacles to deploying the lethal laser.

Northrop Grumman is not satisfied with the significant breakthrough. They want to continue to shrink the device so that one day it might be portable on the battlefield. Dan Wildt, vice president of Northrop's directed energy systems program, adds, "It is still a little heavy and a little big."

What's neat is that its actually the same "compound laser" concept as the Deathstar. Don't know what they mean by "high power requirements" as 100 kw is only about 140 hp, meaning even small vehicles like APCs could supply the power.

[phred]

Isn't the 105kw the output? It could be that it's not very efficient and sucks up a lot of juice getting to that point.
I can see it being used as an anti-missile battery on a carrier or something though.

WTG Northrop Grumman!

[Modax]

Wikipedia says that a Bradley APC's engine gives 600 HP. So even if we assume 50% efficiency for the laser, that gives us a vehicle that can either accelerate hard, or fire its laser, but not both at the same time.

[Fingolfin_Noldor]

Oh, they finally managed to do the Beam Combining for 100KW right. What they did was essentially lay down multiple laser trains of .. 15 KW each using Nd:YAG ceramics, stack them next to each other, apply phase matching through electronic feedback, and let the interference pattern generate a high intensity central maxima of 100KW.

There's another team from Textron which in my opinion has a better configuration. It's essentially a single laser train of multiple 15KW modules.

[Sea Skimmer]

Wikipedia says that a Bradley APC's engine gives 600 HP.

Yup, early ones had 500hp, starting with I think the A2 model its 600hp. For comparison a Stryker has 350hp, and most MRAP designs have about a 300hp engine. A British Warrior has 550hp, and the Russian BMP-3 about 500. The new German Puma has close to 1,100hp, though it also weighs a fair bit more then any other infantry carrier on earth except tanks converted to the role by Israel.

So even if we assume 50% efficiency for the laser, that gives us a vehicle that can either accelerate hard, or fire its laser, but not both at the same time.

That’d be very true if the entire output of the engine could be channeled into an alternator, but right now it can’t be. We just didn't design anything that exists right now that way. Existing armored vehicle power packs only have alternators to meet the vehicles basic electrical needs, and even charging up batteries for soldiers equipment and running new computer gear can present a significant strain. That was one of the minor things that Stryker and now the various MRAP designs really improved upon, since they were some of the first AFVs designed in the modern electronics era when every solider has an Ipod and a camcorder that damn well needs juice or else moral will suffer. None of them are hybrids, but none the less they had proportionally bigger alternators and better wiring then anything before.

So for future developments which need way more power in turn (for various radar/ladar/satcom systems) all vehicles will be hybrid. For a laser armed vehicle this means it would fire the thing using its batteries, perhaps additionally buffered by a capacitor to reduce strain on the batteries from rapid discharge. When using the laser the engine would just run at a high idle, and you’d always have full power for acceleration if you need it.

If we ever get really high power (several megawatt) compact lasers on vehicles then we’ll move over the pulse alternators which are already being pursued for powering railguns.

A pulse alternator is an alternator which is spun up to a very high speed while generating no electricity, and then the circuit is completed while the input shaft is disengaged. The result is the alternator generates a tremendous current for the short instant during which it spins down. Then you spin it back up for the next shot. Right now this is much more economical in weight and volume then capacitors, though future capacitor developments may change that. Obliviously, we’d want to avoid a system that relies on moving parts if possible but it’s a real option.

Cooling the laser and making it work at all are far bigger problems then electrical power.

[Fingolfin_Noldor]

A better and more informative article:

http://www.laserfocusworld.com/display_ ... 00-kW-mark

Northrop Grumman's electric laser tops the 100 kW mark

March 18, 2009--Northrop Grumman Corporation (Redondo Beach, CA) has produced the most powerful beam yet created by an electric laser, measured at 105.5 kW. The solid-state laser is made up of seven 15 kW plug-and-play units, each 38 in. x 28 in. x 12 in. in size, not counting the electrical power supply and the heat sink.

The company claimed ownership of this record by completing the final demonstration milestone of the U.S. military's Joint High Power Solid State Laser (JHPSSL) program, Phase 3. The achievements included turn-on time of less than one second and a continuous operating time of five minutes; the laser's electrical-to-optical efficiency was 19.3% and the beam quality better than 3.0. (Last year, Northrop Grumman's laser reached a JHPSSL Phase 3 power level of 15.3 kW in March, and a power level of 30 kW in September.)

"Our modular JHPSSL design makes it straightforward to scale laser-weapon systems to mission-required power levels for a variety of uses, to include force protection and precision strike missions for air-, sea- and land-based platforms," says Dan Wildt, vice president of Directed Energy Systems for Northrop Grumman's Aerospace Systems sector. He notes that the 100 kW threshold has been viewed traditionally as a proof of principle for "weapons-grade" power levels for high-energy lasers, but many militarily useful effects can be achieved by laser weapons of 25 kW or 50 kW, if they have good beam quality. "With this milestone, we have far exceeded those needs," Wildt adds.

Each building block for the laser consists of a laser amplifier chain, with each chain producing approximately 15 kW of power in a high-quality beam. Seven laser chains were combined to produce a single beam of 105.5 kW. The laser already has been operated at above 100 kW for a total duration of more than 85 minutes. A government team reviewed results of the demonstration during a System Test Data Review held Feb. 10 at Northrop Grumman's Directed Energy Production Facility in Redondo Beach.

The laser's seven beams are combined by "tiling" them in a row and matching their phases, thus coherently combining them, says Wildt.

The modular nature of the laser means that weapons could be created that emit as little as 15 kW (one laser chain) or as much as 120 kW (eight laser chains--a configuration not yet tested). Jay Marmo, Northrop Grumman's JHPSSL program manager, points out how the company's building-block approach also readily enables more-challenging missions that require well above 100 kW of laser power with a good beam quality. He notes that, combined with the company's Firestrike laser-ruggedization work, the ability to scale to these even higher powers shows the company's readiness "to bring high-power, solid-state lasers to the defense of our deployed forces." (The Firestrike laser is a ruggedized 15 kW laser unit that is fieldable; Northrop Grumman has announced that the Firestrike is ready for order.)

The technology could be deployed in as quickly as a year for a demo, says Wildt, and in a few years for a fieldable weapon system. The resulting laser weapons would be able to shoot down many types of enemy targets, including rockets, aircraft, unmanned aerial vehicles, missiles, mortar rounds, and swarming boats (an attack consisting of many small, explosives-laden boats that converge on a single ship).

The above laser can be operated with pulse alternators only in pulse mode. Pulse mode does result in pulses with high peak power, but if it's continuous power you want, you will need something a more reliable power supply. The system has been fired for 84 minutes. Cooling is either water or coolant if I am not wrong.

[CaptainChewbacca]

So, as it is now its impressive, but not terribly portable. What's its effective range? Can it swat down aircraft or missiles?

[Fingolfin_Noldor]

So, as it is now its impressive, but not terribly portable. What's its effective range? Can it swat down aircraft or missiles?

The range is dependent on the optics provided. A ball park figure for beam-waist beam-divergence product is M^2 * wavelength/pi. So the optics must compensate for the higher divergence rate. In theory, you know, you could focus the beam all the way to 1km away with no problems with a combination of adaptive optics and high quality silver mirrors.

[Sea Skimmer]

The above laser can be operated with pulse alternators only in pulse mode. Pulse mode does result in pulses with high peak power, but if it's continuous power you want, you will need something a more reliable power supply.

Pulses are more realistic and more effective in many cases, because when you start vaporizing a target (unless it’s a high speed missile) the impact area is rapidly obscured by the vapor, scattering the beam. Firing in pulses gives a moment for the vapor to clear away. Of course you can also just have more then one pulse alternator, but like I said it only makes sense for really high power applications, not 100kw.

[Fingolfin_Noldor]

Pulses are more realistic and more effective in many cases, because when you start vaporizing a target (unless it’s a high speed missile) the impact area is rapidly obscured by the vapor, scattering the beam. Firing in pulses gives a moment for the vapor to clear away. Of course you can also just have more then one pulse alternator, but like I said it only makes sense for really high power applications, not 100kw.

True.

The way I see it, is that you will need one constant power supply and an alternator to drive whatever is used to pulse the laser, be it an Electro-Optic Modulator (EOM) or Acoustic Optic Modulator (AOM) which modulates the amplitude of the laser beam. Northrop Grumman's laser is a MOPA laser, where there's a seed laser and an amplification unit, which happens to be the 15KW units mentioned. Nd:YAG ceramic slabs are used to amplify the seed laser, and rows of diode bars are used to pump the slab to initiate population inversion and the seed laser triggers the stimulated emission. The EOM and AOMs placed in the laser cavity are used to modulate the amplitude of the laser beam within the cavity and then generate pulses These modulators are placed inside the laser cavity itself and require fairly high voltage to run.

[Starglider]

Power-to-weight on solid state lasers must be close to surpassing that of chemical lasers now, if it hasn't already done so. The COIL on the YAL-1 weighs 18 tonnes (not including support equipment) and puts out 5-second pulses in the 'megawatt range'; I doubt this laser weighs more than a couple of tonnes. In retrospect chemical lasers will be a brief interim measure, barely deployed before 'real' laser weapons became available.

[Sky Captain]

How long before lasers like this are miniaturized enough to put them in fighters? Imagine fighter combat with LASERS

Although at first such lasers might be deployed on ships where size weight and power requirements are not much of an issue for anti missile defense. Also does anyone else has thought about possibility of using laser as a long range assassination weapon for example Mossad or CIA killing an unwanted person from aircraft flying in neutral airspace dozens of kilometers away with no evidence left.

[Starglider]

How long before lasers like this are miniaturized enough to put them in fighters? Imagine fighter combat with LASERS

The intent is to make a laser that can fit into the central bay on the F35A and F35C; the area that holds the lift fan on the VTOL versions and is empty on the CTOL versions (it also has a convenient shaft drive for a compulsator from the engine). I got the impression that main goal is ground attack, not AAM defense, but having strike capability limited purely by the aircraft's loiter time (rather than ordinance carriage) would certainly be revolutionary. At the rate research is progressing having this weapon in service within ten years seems plausible.

Also does anyone else has thought about possibility of using laser as a long range assassination weapon for example Mossad or CIA killing an unwanted person from aircraft flying in neutral airspace dozens of kilometers away with no evidence left.

There has been some shrill blogging about 'plausibly deniable kill capability' but again AFAIK only in the context of air-to-ground, not air-to-air.

[Sarevok]

What good would a aircraft laser be in ground attack role when fighting strong enemy nations ? Only thing it can reliably kill is humans at short ranges. Flying close to zap foot soldiers in face of long range SAMs and ground based lasers would not be wise.

[Starglider]

What good would a aircraft laser be in ground attack role when fighting strong enemy nations? Only thing it can reliably kill is humans at short ranges.

On the contrary, the Advanced Tactical Laser (a COIL laser currently fitted to a C-130, but theoretically mountable on a V-22) can destroy light vehicles and soft infrastructure targets from a range of 20km (subject to atmospheric conditions, and I believe they've only demonstrated 10km so far). That's a sub-megawatt pulse laser.

Flying close to zap foot soldiers in face of long range SAMs and ground based lasers would not be wise.

Effective MANPADS range is under 5km, none of these lasers (in weaponised form) would require you to approach that closely.

[JointStrikeFighter]

How long before lasers like this are miniaturized enough to put them in fighters? Imagine fighter combat with LASERS

The intent is to make a laser that can fit into the central bay on the F35A and F35C; the area that holds the lift fan on the VTOL versions and is empty on the CTOL versions (it also has a convenient shaft drive for a compulsator from the engine). I got the impression that main goal is ground attack, not AAM defense, but having strike capability limited purely by the aircraft's loiter time (rather than ordinance carriage) would certainly be revolutionary. At the rate research is progressing having this weapon in service within ten years seems plausible.

Minor nitpick, but it isn't empty; they just chucked a fuel tank in there.

[Count Chocula]

Hmmm, I've read up about these kilowatt range lasers, but this is the first report of a compound laser I've seen. Regarding power generation, these suckers could be great for population center defense if they're on rails.

Think about it: a Diesel locomotive already has a 3,000+HP engine driving a 560kW generator, providing a high constant output. Such a powerplant could easily provide enough juice for, say, four cars: two laser cars, a radar/sensor/JTIDS feed car, and a sleeping cabin. They'd be mobile, survivable, and viable...all the things that rail-deployed MIRVs are, but for defense. Very cool.

[Fingolfin_Noldor]

Hmmm, I've read up about these kilowatt range lasers, but this is the first report of a compound laser I've seen. Regarding power generation, these suckers could be great for population center defense if they're on rails.

Think about it: a Diesel locomotive already has a 3,000+HP engine driving a 560kW generator, providing a high constant output. Such a powerplant could easily provide enough juice for, say, four cars: two laser cars, a radar/sensor/JTIDS feed car, and a sleeping cabin. They'd be mobile, survivable, and viable...all the things that rail-deployed MIRVs are, but for defense. Very cool.

One of the major trends laser engineers and physicists are pursuing these days is to use methods to combine laser beams into one single beam. There are several methods available, and the Northrop Grumman team here used Phase locking, where you lock the phases of all the laser beams and tile the lasers as close as possible. In the far field, you will see diffraction interference pattern, with a central maxima. Other methods include spectral combination, where you select specific wavelengths in the right order and use a diffraction grating to combing them into a single beam. A lot of this makes use of the principle of reciprocity which applies to many optics setups. The Northrop Grumman team are by no means the only people who have published about their methods. Others have as well.

[lance]

What can a 100Kw laser do? Does anybody know?

[Fingolfin_Noldor]

What can a 100Kw laser do? Does anybody know?

Fry... mortars? Shells? Missiles?

[Balrog]

What can a 100Kw laser do? Does anybody know?

Fry... mortars? Shells? Missiles?

Perhaps taking out lightly-armored vehicles? 100kW would be overkill for sniping soldiers though.

[Elheru Aran]

What can a 100Kw laser do? Does anybody know?

Fry... mortars? Shells? Missiles?

Perhaps taking out lightly-armored vehicles? 100kW would be overkill for sniping soldiers though.

Makes one wonder what one such would do if it hit a human. Explosion of superheated steam/giblets?

[Starglider]

Makes one wonder what one such would do if it hit a human. Explosion of superheated steam/giblets?

100 kW is enough to flash-vaporise about 50cm3 of flesh per second (if fully absorbed and evenly distributed), so it'll probably be fairly messy, but it wouldn't blow the person apart.

[Sea Skimmer]

A laser like this could disable, though not utterly destroy, any piece of military equipment not buried in at least a weak bunker (dirt and concrete will take a long long time to burn through). Tanks, artillery, trucks, ships, could all be rendered combat ineffective by damaging key pieces of external equipment such as gun barrels, sights, road wheels, tracks or tires. The enemy could repair everything (well, not a gun barrel, but they can replace it at a depot), unless you match to start a fire onboard which is not unlikely, but you do this enough and you’d seriously eat into his combat power. Imagine an F-35 with a laser and eight Small Diameter Bombs comes in, destroys six or seven vehicles with the bombs, then damages even just one or two more with a laser, that’s a significant boost to how much it’s accomplishing in one sortie vs. bombs alone.

In addition, the US Army has already fielded a 1kw laser which can burn through the casing of bombs and artillery shells and explode them. That means just about any exposed piece of ammunition can be destroyed, though some types of explosives would just burn or produce only a low order detonation. Still that’s damn useful. Goes without saying that we can kill people too, and aircraft and missiles are in deep shit.

The main need for more power is so that targets can be engaged more rapidly, and so that effective range will be much higher. Effective range on a 100km laser wont be too high, making it hard to employ from an aircraft that has to remain above 15,000 feet for its own safety.

Makes one wonder what one such would do if it hit a human. Explosion of superheated steam/giblets?

A little one maybe. Some of that person would be literally just burned away or vaporized. Its going to inflict a deep burn on the area it hits, and since that person is going to move the instant it hits, that will be a big area. It’s not impossible a person would be cut in half though dwell time and the range would matter a great deal.

[Tahlan]

It's all very interesting. However, my question is: Where are the other nations of the world in laser development? Allies and antagonists? The USA can't be the only country developing lasers. Are we leading the way or are we going to get smoked like a cheap cigar by another nation?