How do they work?
A sertain ammount of radiatio, when passed through the chrysal, stimulated the millecules in the chrystal and creates a force field of pure energy. The chrystals that emit the red glow pruduce the purest energy (By a tiny ammount, not even worth worriing about) thus they are slightly more powerfull, but are in fact slower. Gree is the fastst saber, blue is an inbetween.
I read this in a book somewhere, I cant really remember.
Taken from the SW fact file Weapons section
LIG2 (Darth Mauls sabre)
When the lightsabre is activated, a tremendous charge of energy flows from its power cells. This is focused into 2 tight, parallel beams by a series of multi-faceted Adegan crystals or jewels, which causes the blades' red glow. The blades are formed via beam emitters and projection plates, arcing back to a negatively charged high energy flux aperture.
LIG4 (Luke Skywalkers Green Sabre)
Unable to buy an Adegan crystal Luke was forced to synthesize one in a small furnace. More sophisticated sabres have 3 crystals to allow adjustment of blade length and amplitude. Due to the time it took to make one Luke couldn't consider making all three.
There isn't anything that says how the blade colour is produced therefore I assume its down to the colour of the crystals used.
all we can presume is they have some sort of power cells, some cut scenes from TPM shows that Obi Wans saber doesnt work thats why he is just running from that droid scout. There have never been any explanation on how sabers or blasters work though so we really wouldnt know.
And I bet we wont learn it in Ep III either.
So for those who reads those eu books you can go with that explanation used and just accept it (OPTION1). For those who just are into canonical stuff have accepted it is just part of the technology they have, just as they are able to travell faster than the light.(OPTION 2)
But as of this thread we go with OPTION 2.
Option 1 has a whole forum of its own called
Star Wars: Literature & Expanded Universe
here's what i've heard, the light sabre is actually a looping laser, and it has to be condensed tightly together to produce the light sabre, the crystals which both power and give the lightsabre its color are from different places. As you all must know, the Sith were banished, well where they were banished to, i don't know, but it must have had lots of red crystals, which is what all those on the dark side use as their light sabre. And in Ep 4, the one given to luke looks more white, but that was at the early stages of making light sabres... (For those who think light sabres may exist) in the movie, as a post production effect.