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Author Topic: lasers and reflective targets  (Read 4217 times)

Offline that mad man

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lasers and reflective targets
« on: 22/02/2007 17:16:22 »
Hi.

It has just been announce that a solid state laser has now reached 67kw of power in a laboratory and may reach a 100kw "magic" figure soon enabling it to be used by the military to shot down targets.
A while ago a laser gun was in development that was alleged to be able to temporarily blind people.

Surly if the target was mirrored or very reflective this would render the lasers useless, a shiny rocket or a mirrored pair of sunglasses for example, also any path of the reflected beam would be unpredictable.

Are the lasers used in this case different?

TMM





 

Offline syhprum

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lasers and reflective targets
« Reply #1 on: 22/02/2007 19:03:16 »
Although the 67KW figure is impressive surely what is more relevent is the output in Joules i.e how long can this output be maintained? 
 

Offline lightarrow

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lasers and reflective targets
« Reply #2 on: 22/02/2007 22:00:34 »
Hi.
It has just been announce that a solid state laser has now reached 67kw of power in a laboratory and may reach a 100kw "magic" figure soon enabling it to be used by the military to shot down targets.
A while ago a laser gun was in development that was alleged to be able to temporarily blind people.
Surly if the target was mirrored or very reflective this would render the lasers useless, a shiny rocket or a mirrored pair of sunglasses for example, also any path of the reflected beam would be unpredictable.
Are the lasers used in this case different?
If they really can be used from the military, I doubt there will be much of information about them. Apart the total energy delivered, as syhprum pointed out, a very important parameter is frequency, and the ability or not to change this frequency (and maybe, the plane of polarization) continuously in a fast way.
In the UV spectrum, for example, it is less probable for a material to reflect the radiation. For X-rays, almost impossible (but it's not this the case).
Furthermore, I assume that if frequency could be changed, and very fast, it could be possible to match it with the optimal absorption frequency at every instant, even if the physical/chemical properties of the body change continuously because of the very absorption of EM radiation.
(The plane of polarization is important because a surface have the max absorption for an EM radiation which plane of pol. is pependicular to the surface).
« Last Edit: 22/02/2007 22:10:28 by lightarrow »
 

Offline syhprum

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lasers and reflective targets
« Reply #3 on: 23/02/2007 05:51:00 »
Quite a bit of information is available here

http://news.bbc.co.uk/1/hi/sci/tech/6380789.stm
 

paul.fr

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lasers and reflective targets
« Reply #4 on: 23/02/2007 06:05:20 »
Surely the point is, that this has only been achieved "in the lab". How much longer will it be before the lazer is mobile and "out of the lab"?
 

Offline that mad man

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lasers and reflective targets
« Reply #5 on: 23/02/2007 17:29:20 »
Ahh.

@ thanks syhprum, that's the article that got me thinking.

I just found a site that shows up the problems nicely. Mirrors have been proposed that could be put in orbit thus extending the range and also special contact lenses could be used to protect the eyes. So shiny objects would reflect the beam unless its an x-ray or ultra violet laser.

http://www.defensetech.org/archives/cat_lasers_and_ray_guns.html

Sorry, I hope you don't think this is a political stance as I am interested in the science of it all.


TMM

 

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lasers and reflective targets
« Reply #5 on: 23/02/2007 17:29:20 »

 

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