Ive got a plausible idea for an repeating infra-red laser induced plasma sword. Essentially if anyone has any knowledge of laser dynamics, I'd be very interested to hear your opinions.
The idea is this:
What you need: One compact super high wattage (maybe 40,000 watts) infra red repeating laser (about 100Hz) with a nice thick beam width (not sure of exact nM)
This is routed through a very dense conical/cylindrical laser splitter (i designed a quite plausible concept diagram if anyone's interested) which splits the beam around 400 times.
Each beam is then routed through a couple of mirrors to get it at the correct angle, and then focussed through it's own small lens to a point in space in front of the lens array (typically making up a straight line with each point for a sword shape) the lens array would consist of 400 small focussing lenses each in a different position obviously.
When each of the split beams is focussed in thin air, you would get 400 "dots" of laser plasma emission each repeating at 100hz to make up your buzzing psuedo-solid (at least to the human eye) plasma "sword" of a length of about two feet??
Here's what I couldn't find out:
Although I know that Infra red lasers are essentially heat lasers I couldnt find out what the temperature of the thin air plasma emissions they create are - any help?? The sword would still be choppy because of the fact that each of the "points" of plasma is reinforced by its own focussed point of hot infra red laser light.
There would also be problems with having the blade directly pointed at you (or even within about 20 degrees angle depending on the lens array) as it would probably blind you instantaneously - but hey, you'd still have a plasma sword, and you'd be fine as long as you stayed on the handle end of it! You also run a small risk of being struck by lightning too as I understand it?? hehe
I guess the stronger the laser wattage, and the faster the repeat rate, the stronger/hotter the sword? I suppose there would be a limit on this eventually due to the air not collapsing inwards fast enough after each refresh??
So all you laser geniuses out there tell me what you think??
I have illustrations I made if I haven't described it adequately for the imagination.......
for an example of this tech in action pls see: www.physorg.com/news11251.html-- Half-life below 40yrs, Jun 08 2006 Lightsaber Factoids http://en.wikipedia.org/wiki/Lightsaber [tcarson, Jun 09 2006] Do you know what a 40,000 watt laser can do? No? Neither do I. What I do know is that a 40w laser is a pretty bloody big one by today's standards (and it aint no hand-held job either).-- methinksnot, Jun 08 2006 And welcome to the halfbakery [0.5life<40yrs]-- methinksnot, Jun 08 2006 Hey - I didn't say it wouldn't be hefty, hehe - but prototypes usually are aren't they? 40000 Megawatts might be a bit pessimistic seeing as japanese scientists have managed to do it with less....-- Half-life below 40yrs, Jun 09 2006 well I know it would burn the living bejeezus out of whatever you pointed it at?? is that enough for support for the concept? : )-- Half-life below 40yrs, Jun 09 2006 one of these 2000 watters would probably do the job:
Nuvonyx Inc. ISL-2000L Solid State Diode Laser 2003 Model / Complete Package, 2000 Watt 808nm solid state diode laser / 208V 3 Phase with control unit and 300 Watt cooling capacity chiller / Approximately 168 hours on the laser and 300 on the chiller / Used on an R&D project / Unit includes 100 microsecond pulsing option / operates in both CW or pulsed mode, electronically adjusted with touch screen controller / 2.9" focal distance with a 1mm x 12mm spot size / Does not include robot but can be purchased separately (Price US Dollars $72,000.00-- Half-life below 40yrs, Jun 09 2006 //well I know it would burn the living bejeezus out of whatever you pointed it at??// And whatever is behind that, and behind that and behind that and maybe even a bit to the sides of that too.-- methinksnot, Jun 09 2006 You didn't mean "sword". Did you? It was in jest; tell me it was in jest and that you didn't expect anyone to be waving this planet-splitter around.-- methinksnot, Jun 09 2006 rather than splitting the laser into 400 smaller beams, why don't you sequentially focus the laser along the line of the sword - if you do this fast enough you will at least have the illusion of a continuous plasma sword.
The sequential focus could be achieved with a ellipsoidal mirror that changes in shape (with one ellipse focus moving along the line). This could be done with a micro-mirro array.-- xaviergisz, Jun 09 2006 uhmmmm, its a laser, it does not stop at any point, 2 feet out or 2 million miles out. I am a little unclear as to how this brings you to a sword. This thing will cook everything within line of site that comes in contact with the beam.-- jhomrighaus, Jun 09 2006 [jhomrighaus], I think [Half-life below 40yrs] hopes that if you can focus a laser (of the right frequency) to a tight enough point, the air at the focus will spontaneously turn into a plasma. Any of the laser beam that is not absorbed/dispersed by the plasma will diverge from that point, thus being relatively harmless.
Of course this whole invention appears to be wildly optimistic.-- xaviergisz, Jun 09 2006 aha - you hit the proverbial nail on the head xaviergisz have a look here and get back to me peoples:
www.physorg.com/news11251.html
if theyre considering using it as a display technology........hmmmm?
I like the idea of the ellipsoid, but that would require moving parts? or am I wrong....I was just going for fixed parts for stability-- Half-life below 40yrs, Jun 09 2006 perhaps you should alter the title to include the word light sword (or more accurately light sabre) if you want more response. (I'm not saying you should, just that's what will happen.)
Do you not object to a re-directing mirror at the perceived neccessary reach of the sword? (of course, you will have to have a re-re-directional mirror back in the handle - very complicated.)-- Zimmy, Jun 09 2006 done : )
as for the mirror I'm not sure theres a need - are you talking a mirror at the end of the plasma??? not sure I caught your meaning there....-- Half-life below 40yrs, Jun 09 2006 This is completely off topic, but can someone tell me if a mirror will absorb any of a laser's energy if it strikes it, or would it be total reflection?
Does it depend on the kind of laser or the kind of mirror? Could I defeat a Jedi with a really flat piece of tinfoil?-- notmarkflynn, Jun 09 2006 yes it depends on the type of mirror notmarkflynn there are several types - and chances are that the hot plasma would burn through the foil before you could redirect the laser beams!
of course with my version I could just point it at you from a safe distance and blind you so you couldnt use your devestatingly clever 'bit-of-foil" technique, hehehe
darth vader says: "The foil is strong with this one"-- Half-life below 40yrs, Jun 09 2006 I really wish I could go just ::one:: week without being shot with a laser. Just one.-- notmarkflynn, Jun 09 2006 for more wild speculation as to the workings of lightsabres, check out the wikipedia article on them. full of details, speculation, and context.
while i doubt you'd be able to lift this thing, and i admit it's a bit off topic, how will you power it?-- tcarson, Jun 09 2006 holy crap! I never thought you would really do it. I hope you're up on your science. I was just making a joke. (I predict about 20 people telling you why this won't work.)-- Zimmy, Jun 09 2006 //how will you power it?//It has its own switch at the power station.-- methinksnot, Jun 09 2006 This idea has much more death star than lightsaber in its parentage.-- GutPunchLullabies, Jun 09 2006 no [gutpunch], it's more darksaber than deathstar. less of a planet, fewer TIE bays, stormtroopers, sith lords.-- tcarson, Jun 09 2006 ...and built by a Hutt? That's not very nice.-- david_scothern, Jun 13 2006 [marked–for-deletion] annoyingly long title pisses off grumpy old scientists.-- ConsulFlaminicus, Jun 13 2006 lol!-- Half-life below 40yrs, Jun 30 2006 Along the lines of a joke about not needing a Porsche if you are endowed adequately in the trouser department - if you've obtained a 40kW laser, are you quite sure you really *need* a light saber?-- BunsenHoneydew, Feb 29 2008 random, halfbakery