posted on May, 5 2004 @ 11:39 AM
Let me offer this up as an initial disclaimer; anyone who is in weapons and countermeasures development knows that no system is 100%.
Now on with the show...
Nans, your first statement refers to the "principal problem in development of high power laser"(s):
Nans: "The construction of optical able to support high energy charge (This problem dont exist with X-ray LASERs)"
You are absolutely right, the optics which include mirrors and lenses on a weapons grade high power laser must be of an extremely high quality but
this is already a non-issue with the current field of high energy lasers. The optics of such devices are usually sealed to keep out foriegn particles
that could cause an internal meltdown or combustion. Much of the weapons quality optics comes from German firms that are highly experienced in
ultra-high quality optics under contract through TRW/Northrop and Raytheon.
Your next point...
"Devellopement of movable plate-forms of targeting, with a high power source : (This problem is impossible to solve for the space system, because
of the tons of chemicals needed)"
Your conclusion that chemical lasers powerful enough to be used from space are not feasible as weapons due to being far too heavy to transport into
orbit is correct. There are at least 2 ways to get around the weight issues:
1. Break down the laser into seperate parts and send it into orbit on multiple launches as opposed to a single launch - then assembling the seperate
parts once all are in orbit.
2. The Second option is to simply wait until solid state weapons grade lasing devices are potent enough to be applied to targets from space. Solid
state lasers in space will also not have as much of the cooling issues that land based high power solid state lasers are currently experiencing. At
the current rate of development, the wait for such space-based devices will be less than the 5 years estimated to deploy land based devices.
The next issue you bring up is Nans: " Possibles counter-measures...
Missiles can be cover with a film of Phenol-Carbon : vaporized by the laser beam, this film would create a protection plasma during a few
2 points that should be made regarding plasma being used to sheild against a laser.
1. As you have already stated any such shielding would last a very short amount of time considering the volume of energy a laser weapon of this
caliber would produce. "A few seconds" is a really optimistic estimate for a "film"-like coating.
This is similar to having a bullet proof kevlar vest able to withstand a 357 magnum and declaring you are immune to bullets - only to have someone
shoot a 105mm howitzer point blank into your chest. The ABL and MTHEL have a massive focused output and it is doubtful that any such coating on an
airworthy missile or artillery shell would prolong the inevitable for more than a few nanoseconds.
2. The next issue regarding plasma protection of a missile or artillery shell centers around the actual method. The idea of using a plasma shield goes
something like this... a directed energy weapon fires at the protected missile and the DEW's energy is caught up within the plasma’s electromagnetic
fields and dissipated or deflected into the surrounding airspace.
This kind of defense is problematic in that the temperature of the plasma produced by a high energy laser weapon would aid the laser not hinder it in
destruction of the missile. So hot plasmas while dense would only serve to help in the destruction of the incoming missile, not protect it.
Theoretically COLD plasmas can be made denser and could deflect a particle beam or laser attack but it would also depend on what type of laser is
being shot at it and how high you can tune the plasma frequency. Presently, a film coating of plasma generating material does not produce cold plasma,
and you cannot "tune" the frequency of the plasma to fit the lasing device being shot at it, also the weight and energy requirements to produce
cold plasma are not currently feasible on a missile or artillery shell using technology available now or for years to come.
There are also inherent issues with infrared lasers and the ability of plasma to reflect or deflect high power IR beams. It is certainly possible but
the issues involved present definite cost, logistic, weight and technical problems for protecting a missile where weight and areodynamics are an
There is a good read on this in a paper entitled, "The Plasma Mirror: A Subpicosecond Optical Switch for Ultrahigh Power Lasers" by B. Dromey and
I believe it will help explain these problems better.
Another countermeasures method you bring up is this...
Nans: "polish the missiles surface (The energy would be send back to the source, directly)"
If you are implying that a polished missile surface would reflect back and do harm to the DEW firing at it - this just is not going to happen.
A missile by design is cylindrical in shape and from a DEW/laser perspective is like shining a flashlight onto a convex mirror which deflects the beam
of light in all directions - definitely not a full strength reflection directly to the DEW attacking it.
What you must now be thinking is if the laser's beam is deflected in all different directions then the laser's effect is nullified - this question
was also posed by Laxpla a few entries up on this thread.
The effects of the laser are however not nullifed - Here's why:
1.) No surface is 100% reflective.
The energy that is not reflected is dissipated by the surface as heat. As heat builds up, the reflectivity of the surface will decrease, and it
decreases exponentially from that first contact. Obviously this will increase the time it takes for a laser to inflict damage on a target, but at the
power levels we're talking about, it would be measured in nano or milliseconds as opposed to seconds.
It bears mentioning that mirrors for industrial lasers need to be water cooled, in spite of being over 99.5% reflective for this reason.
2.) For a surface to remain highly reflective, it has to be kept incredibly clean. A $600 germanium mirror for a 500 watt CO2 laser can be easily
destroyed in a fraction of a second if it has so much as the residue of a finger print that has been wiped off with a lens cloth without benefit of
For tanks/aircraft/missiles to be able to reflect enough of a weapons-class laser beam to be impervious, they'd need to be polished to an optical
grade and wiped off up to clean-room specs. Not the sort of thing that's practical in combat.
You must also consider that as the projectile flies through the air/atmosphere the heat generated, the humidity, air pollution, dust particles and
general oxidation cause surface anomalies imediately upon being fired or launched - this spotting on the projectile gives the attacking DEW ample
nonreflective surface area to heat and thereby neutralize it.
3.) As alluded to while discussing plasma shielding, surfaces are only reflective to a certain range of wavelengths.
As an example, the germanium mirror I talked about above is reflective to CO2 lasers in the far infrared wavelengths (10.6 microns), it is glossy
black and completely unreflective to visible light which as a reference centers around .4 microns.
On the other hand, a mirror for a Ruby laser, which outputs radiation at .69 microns is standard silver. If you switch the two with their respective
lasers, each will shatter immediately.
If an enemy were to armor their vehicles/missiles with a reflective coating, provided they could keep it clean and polished throughout it's flight
trajectory (impossible unless in a particle free perfect vacuum), the resonant cavity optics of the laser could theoretically be changed to amplify a
wavelength that the shell or missile would be vulnerable to.
The ultimate laser weapons goal in the future is to have a free electron solid state laser - the laser operator could select any wavelength desired at
the push of a button neautralizing the effectiveness of reflectivity and therefore decreasing the power needed to accomplish what is now accomplished
with multiple megawatt devices.
Your best bet for negating the effect of weaponized lasers:
One weapon that a DEW/laser would no doubt have a problem destroying is a non-explosive artillery round. There is no fuel to heat up and no explosive
to ignite. The heat of the laser could possibly cause it to veer off course but consider this... the space based "Rod from God" concept where a non
explosive steel rod is fired at a target on earth's surface from a satellite in orbit. The sheer speed of the weapon and it's weight/mass would
cause great destructive impact. The speed, the fact that there is nothing to explode or ignite could very well impede a laser weapon's ability to
defend it's valued assets.
Another similar option would be an EM rail gun firing non explosive rounds where, once again the sheer speed involved makes it highly destructive.
Well, that's enough for now, I have meetings to go to and will check on this thread later.
[Edited on 5-5-2004 by intelgurl]