U.S Navy now have laser weapon deployed with permission to use.

Having a ten mile range is pretty much useless against a missile traveling 3000 mph. That only a few seconds flight time. That's ok for slow targets but what about the boat launching missiles from eleven miles away?
This will be a fun weapon to see develop.

a reply to: VirusGuard

You're quite correct, since the projectile fired from the railgun is (at this time at least) a "dumb" weapon, it's really only effective for stationary targets or targets with predictable paths.

Still, I drool over Railguns.

Obviously.

a reply to: intrptr

In regards to the atmosphere, clouds and bad weather, lasers that operate between about 500nm and 1350nm are subject to varying degrees of atmospheric attenuation, the greater the wavelength the greater the energy loss (attenuation) over distance. However, 270 to 430nm lasers have been proven to have much less attenuation, they can even penetrate water to hit close-to-surface-submarines. I am not sure what the operational wavelength is of this particular laser system, but I expect they Navy would have gone for something less that 450nm (blue --> ultraviolet) as this is pretty much common knowledge, at least for anyone working with lasers.

Cheers - Dave

a reply to: bobs_uruncle

That was real useful info, Dave. Laser that work underwater? Wild…

Laser energy over greater distances in air are also pulsed to drive through the atmosphere over greater ranges?

Time on target might be nearly instant, but destruction of the threat can take longer.

a reply to: lonesomerimbaud

Thats freaking awesome. Its things like this that make a dollar collapse, foreign militarys advancement or other threat irrelevant.

Lasers....we got them. Lol

a reply to: bobs_uruncle

... the greater the wavelength the greater the energy loss (attenuation) over distance. However, 270 to 430nm lasers have been proven to have much less attenuation

Hum not so sure about this. I've done some informal study on the subject some year ago and here some comments based on it:

1- Atmosphere and especially battlefields are not simply pure air, the main limitation is almost alway suspended particulate scatterers. Rain is one of them.

2- Military commander require that their weapon system work "all weather"; In combat you don't have the luxury to wait for the weather to clear up.

3- In operation theater, there is heavy use of combat obscurant (artificial fog). This is the main reason Willey Pete bomb (white phosporus) is still allowed to be used. Remember Sadam and his petrol fire in Bagdad to produce smoke to jam the laser guided bombs.

4- Particulate scatterers can be penetrated up to a specific depth using the longest wavelength possible. If you see nothing in visible wavelength, there is some advantage in the 3 to 5um band and the best penetration will be 8 to 14um. RADAR will be much better. See Mie scattering theory.

5- Marine environment is specific and perticularly harsh, you have suspended particules of salt in the air with the added bonus that they corrode everything.

6- Small wavelength like 270 to 430nm produce strong Rayleigh scattering even in pure atmosphere, this is why a greeny laser pen produce a green line in the air, even in the absence of suspended particules.

originally posted by: Hoosierdaddy71
Having a ten mile range is pretty much useless against a missile traveling 3000 mph. That only a few seconds flight time. That's ok for slow targets but what about the boat launching missiles from eleven miles away?
This will be a fun weapon to see develop.

Do you think there will be an enemy surface ship *eleven* miles away, in a hot war, using missiles, against a carrier with an air wing?

The carrier's primary defense against missiles is of course fighter aircraft.

Of course, the threat has always been submarines, and maybe they could get off a missile shot at 11 miles but even then they'd quickly be located and hunted.

A long-range self-guided torpedo from a sub is the true threat. Launch something quiet. Scoot. An hour later a ship sinks, and the sub is 15 miles away in any direction from its launch point.

When i can get the sharks head fitting for my evil lair then i'll be happy

But really it provides an extra layer of protection at no real cost so whts not to like and on a nuke carrier you could probably mount them every 6 inches with no real loss in power

a reply to: lonesomerimbaud

From the article at rt.com:

But lasers have their own peculiarities, with efficacy depending on weather conditions, the presence of dust and vapors in the air, and other factors. The range of the LaWS, which is limited by those factors, remains classified.

Usually when a weapon system have exceptionnal performance, they brag about it. But when performance is not up to expectation, they classify the info.

geez....if I was the enemy, I would buy a 1000 dollar mirror, or, maybe a large fan-shaped water cannon...I might be mistaken, but I think all you need to do, is disrupt the focus of the laser.

a reply to: lonesomerimbaud

My best guess is they used 6x 5KW YLS Series Ytterbium Fiber Laser from IPG Photonics working at 1060nm.

This wavelength make it very sensitive to weather condition.

I hope they used a sapphire output aperture.

a reply to: VirusGuard

Knowing the USA these lazer type weapons will be used on Protestors along with the water cannon.

Shows how well you know the USA now doesn't it?

We use teargas and rubber bullets...water cannons are for rookies.

originally posted by: PeterMcFly
a reply to: bobs_uruncle

... the greater the wavelength the greater the energy loss (attenuation) over distance. However, 270 to 430nm lasers have been proven to have much less attenuation

Hum not so sure about this. I've done some informal study on the subject some year ago and here some comments based on it:

1- Atmosphere and especially battlefields are not simply pure air, the main limitation is almost alway suspended particulate scatterers. Rain is one of them.

2- Military commander require that their weapon system work "all weather"; In combat you don't have the luxury to wait for the weather to clear up.

3- In operation theater, there is heavy use of combat obscurant (artificial fog). This is the main reason Willey Pete bomb (white phosporus) is still allowed to be used. Remember Sadam and his petrol fire in Bagdad to produce smoke to jam the laser guided bombs.

4- Particulate scatterers can be penetrated up to a specific depth using the longest wavelength possible. If you see nothing in visible wavelength, there is some advantage in the 3 to 5um band and the best penetration will be 8 to 14um. RADAR will be much better. See Mie scattering theory.

5- Marine environment is specific and perticularly harsh, you have suspended particules of salt in the air with the added bonus that they corrode everything.

6- Small wavelength like 270 to 430nm produce strong Rayleigh scattering even in pure atmosphere, this is why a greeny laser pen produce a green line in the air, even in the absence of suspended particules.

I agree with most of your points in 1, 2 and 3, even 4 a bit, as any kind of particulate matter, whether solids or liquid tend to case absorption, scattering and/or diffraction and in smaller lasers, say under 10 wprf, atmospheric conditions can seriously inhibit the transfer of energy, but not when you are in the megawatt range. I would disagree on the 270nm to 425nm as I have used them and they transfer very nicely through the air at long distance targets and/or about 25 feet underwater (with sufficient power) to effect targets to their detriment (unfortunately water against metal acts like a big heat sink, so you need a good amount of starting power).

In addition, lasers of reasonable power, say in the 1 MW to 5 MW range (or greater) will actually destroy any particulate matter in the way and clear a path. If you add a nice nuclear source to that and a linear accelerator, you can have some serious fun.

Cheers - Dave

originally posted by: lonesomerimbaud
a reply to: intrptr

Well spotted. That makes a lot of sense. Well may be here is the answer to that threat?

I think the space deployed lasers are not far away. SDI, Reagan's people called it. A dream then and almost a reality now. "Fascinating" as Mr Spock would say.

Back in the 1980's, we didn't have CPU's that were fast enough for the guidance of anti-missile missiles travelling at hundreds of MPH. Clock speeds at the beginning of that decade were 1 MhZ. By the mid-1980s, they were 20Mhz to 60Mhz. Now CPU's are 2 to 4 GHz, multi-core and superscalar. Back then, lasers would rapidly overheat. Using fibre-optics, one large laser is replaced by a few smaller ones, which gives a better endurance.

a reply to: bobs_uruncle

... atmospheric conditions can seriously inhibit the transfer of energy, but not when you are in the megawatt range.

The advertized laser by the OP is rated at 30KW but we can do some calculation for a 1MW assy as you wish.

We will use the assumption that aperture diameter is 0.3m for a radius of 0.15m (15cm), and the beam use this diameter for a non negligible distance.

Area of this beam is: A= Pi*r^2 = 0.071m^2 or 710cm^2

Irradiance inthere will be: I= Ptot/A giving

14.1 MW/m^2
or
1410 W/cm^2
or
14.1 W/mm^2
or
14.1 uW/um^2

This is 14.1 micro Watts onto a surface of 1 micron per 1 micron.

This is straight from my venerable HP. Not a lot of power to "burn through"... You can multiply the laser power by 1000 and your in the milliWatts range. You can pump a lot of power into an inert particule before it vaporise, before that it will re-radiate the thermal energy as do all black body do like crazy (or may I say grey body).

For the beam, it is not possible to have a small diameter beam with low divergence, this is the theory behind any light front and is relative to diffraction. To get a focus point (beam waist) you must start with a large diameter beam. Maybe later I can do the calculation of this expanding beam just to get an idea, but now I'm a little busy...

a reply to: bobs_uruncle

I was forgetting something important; Once the power level is past a specific irradiance, even pure air will suffer a dielectric breakdown (too high the electrical field) that will cause a plasma discharge and attenuate greatly the energy propagation.

OK I've done a quick calculation for the beam waist dimension and if I'm not completly drunk it may give something near what it should.

Assuming 0.3m laser output aperture diameter at 1060nm for 30KW, calculate beam waist at 10Km distance, then irradiance there on target ignoring atmospheric attenuation.

Dwaist ~= (4*lambda)/(Pi*Phi)

where Dwaist is diameter of beam waist
lambda is wavelength of laser (1060nm)
Phi is divergence (or convergence) of the beam (full angle)

Phi ~= aperture/distance = 30uRad

Dwaist ~= 45mm diameter at 10Km (r ~= 23mm)

Area of beam waist ~= Pi*(23mm)^2 ~= 1660mm^2

At 30KW, irradiance in beam waist (target) is 30KW/1660mm^2 ~= 18W/mm^2

18W per square millimeter, this is not an awfull lot of power, The drone they can destroy at this distance is hopefully made of cardboard !!!

The problem with Laser Weapon on ships is that it can be disabled with electromagnet warfare.

That's the problem with going all "digital"

Faraday protection won't help because "burn through" is easier to cause than to protect from. I am of course talking about abilities of Superpowers, not small countries that can't defend themselves anyway.

a reply to: lonesomerimbaud

Naval weapons have been in the news a lot lately. (Perhaps some not-so-subtle warnings to the other Superpowers? And/or a little promo for their upcoming Expo?)

sploid.gizmodo.com...
US NAVY'S FORMIDABLE RAILGUN CAN LAUNCH PROJECTILES OVER 100 NAUTICAL MILES AT 6X THE SPEED OF SOUND

news.yahoo.com...
HOW SUBMARINE WARFARE IS CHANGING
Despite substantial Navy investment to make their subs quieter, countering technology to find subs is also improving.

nextbigfuture.com...
NAVY SLAB LASERS WILL SCALE TO 300-500 KILOWATTS
Ultimately, Naval surface ships could hit surface and air targets up to 10 miles away.

www.onr.navy.mil...
FEB. 1, 2015 - "NAVAL FUTURE FORCE SCIENCE & TECHNOLOGY EXPO"
Some of the topics sound interesting: "Electromagnetic Maneuver Warfare;" "Expeditionary and Irregular Warfare;" and "Assure Access to Maritime Battlespace."

a reply to: MKMoniker

That would be because the Navy is adjusting to the new realities and changing the way they fight.