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What do lasers do?

I

Icosahedron

SOC-14 1K
Lasers are a staple of Sci Fi, but what would they really do?

What are the effects of visible, IR, UV X-ray and Microwave* frequencies? are there significant differences?

*Maser or projected microwave.

I've heard of burn-through and steam explosion damage in flesh, but what would most likely happen? What effect would a laser rifle have on a person? a car? a tree? a house? a mirror? a snowman?

How much would the effects vary with more powerful weapons - artillery or ortillery?

What about blast effects? Would there be any?
 
I particularly like the fact that a sufficiently powerful laser will destroy mirrors before it can be reflected, and the fact that a sufficiently powerful laser will cause its target to explode, thus forming a true "blaster."
 
Yes, I'd heard about mirrors not stopping weapon lasers. Looks like they can destroy a snowman too.
I read the article to say that lasers can be pulsed in different ways to either burn through or blast out a target. This brings in a level of complexity I don't really want IMTU. I would be willing to accept laser blasters, but I'm not too happy with turning a tuning dial and having my laser change from a burner to a blaster!
I also heard (unsubstantiated in this text) that Ortillery size lasers would cause blast effects simply by heating and ionising the air around the beam/pulse.
 
Hi !

At least a blasting laser is much more easy to get than a burning one.
If you send a maximal amount of energy in a pretty short time to a target a blast effect is very likely, because the target is not able to transport energy/heat away fast enough. The material hit by the laser does not only melt, but evaporates explosively.
To get a pretty burning laser is much more complicate as it depends largely on target properties to get the perfect "flow"
.

Regards,

TE
 
I've mostly described combat lasers as delivering an hourglass shaped wound.

The reasoning is simple. A laser hits flesh, carves a hole directly through, the highly energetic material in the wound needs to go somewhere, and there is these handy exit wounds made previously for the vaporised flesh to leave through, these expand both the entry and exit wound and hopefully disrupt more material in turn.
 
Originally posted by Icosahedron:

I also heard (unsubstantiated in this text) that Ortillery size lasers would cause blast effects simply by heating and ionising the air around the beam/pulse.
Click to expand...
The "laser death ray" site talks about how different colors will interact with air.

I think it would be undesirable in most cases, so weapons would mostly be designed to avoid interacting with air when possible. Near infra-red lasers might be chosen for just that reason.


By the way, I forgot to mention that lasers can be used to weld metal!

How cool is that?

http://www.uslasercorp.com/envoy/welding.html
 
Originally posted by TheEngineer:
Hi !

At least a blasting laser is much more easy to get than a burning one.
If you send a maximal amount of energy in a pretty short time to a target a blast effect is very likely, because the target is not able to transport energy/heat away fast enough. The material hit by the laser does not only melt, but evaporates explosively.
To get a pretty burning laser is much more complicate as it depends largely on target properties to get the perfect "flow"
.

Regards,

TE
Click to expand...
Perhaps my use of the word 'burning' was incorrect. 'Boring' might be better - the weapon blasts away small quantities of matter, carving small holes successively deeper, instead of blasting the hourglass cavity right throught the, er, watermelon.
 
Uh oh, mirrors not stopping high power lasers puts a big handwave infront of reflec.

I kind of like the idea of having a power dial on a laser. Blast, burn or extra crispy settings. Just as long as nobody figures out how to set lasers to stun we will be fine. ;)
 
Well, high albedo materials, including mirrors, are generally more resistant to lasers than low albedo materials. However, an anti-laser surface is more likely to resemble white paint than a mirror.
 
On the issue of figuring out Reflec armor what about:

Dielectric High Reflective Coatings (DHR)

Dielectric coating can produce very high reflection (more than 99.8% at designed wavelength). They are commonly used in a single wavelength laser cavity where the lowest cavity loss at a center wavelength is essential. Center wavelength range from 250nm to 2200nm for DHR coatings.

Metallic High Reflective Coatings (MHR)

Red Optronics can offer MHR coatings made of Au, Ag, AI, Cr, or Ni-CR. These coatings are applied where a consistent high reflection over a wide spectral range is required. MHR reflectivity is not as high as DHR coatings but it can cover near-UV, visible and near-IR spectrum. To prevent metallic coatings from oxidization, MHR coatings have dielectric overcoat.
 
The problem is that reflective coatings break down at high light intensities. Any weapons-grade laser will immediately destroy a dielectric surface, and it will blow through a thin metallic surface rather fast.
 
Yeah I can see that with current tech, just wondering aloud if there couldn't be some sci-fi stretch to the idea of a MHR/DHR suit, without snapping too many belief suspenders
It is what, TL10 stuff? And pretty pricey to boot. Maybe some layered crystal lattice gold or something.

Just punting some ideas
 
Ablative armor looks to be highly effective against lasers and even bullets. One problem would be a loss of agility for any armored thing that requires flexibility -- whether it's a human body or a moving mechanism.

(Ablative foam could absorb the destruction of lasers and bullets. It would probably suck against rockets and everything else, though. Also it would degrade rapidly with use, and it would be easy for enemies to estimate its weak spots.)


I think Book 4 Mercenary has an anti-laser aerosol. That looks as though it would be effective -- possibly one might inflate a big plastic baggie with the stuff.

Ships in space might coat themselves with ablative foam.
 
Dan,

The problem with a mirror is that the reflective point will be disrupted and tarnished by the energy incoming. Assuming you could "repolish" the mirror fast enough (say during an attack rather then between attacks) then this would be minimised. The objective is to disperse/reflect/absorb the energy incoming before it imparts enough energy to the "Watermelon" to cause it to go splat.

My personal favorite solution is feild effect mirrors (currently unsupported by real world physics as far as I am aware) which would fit the TL10+ reflec solutions, as the surface was damaged it would self regenerate its reflective properties. Not exactly a force feild - more a surface effect on a solid suit.
 
Ok, so how exactly does a mirror work - on a molecular scale? Is it absorption and re-emission? How does it alter the direction of propagation of a light wave, and how might that process be enhanced/sidestepped at high TL?
 
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