Lightsabers have changed little in the thousands of years of their
employ by the Jedi Knights. Those who believe the Jedi order began on
the ancient world of Ossus point to the abundance of Adegan crystals
in the system as proof. These crystals are ideal for the creation of
lightsabers, as they focus the energy released from a saber's power
cell into the tight, blade-like beam. Early lightsabers did not have
self-contained power cells, and were instead connected by a conducting
cable to a belt-worn power pack. Once unleashed, the power channels
through a positively charged continuous energy lens at the center of
the handle. The beam then arcs circumferentially back to a negatively
charged high energy flux aperture. A superconductor transfers the
power from the flux aperture to the power cell. As a result, a
lightsaber only expends power when its blade cuts through something.
So efficient is the blade, that it does not radiate heat unless it
comes into contact with something.
Some have suggested magnetic fields and plasma:
Shin also recommended adding a degausser sound on top of the other
sounds for the weapon since the sound would be reminiscent of a
Design and create a "magnetic bottle." Since the 1950s, the ability to
contain plasma and other high-energy particles has been done with
electromagnetic containment fields, otherwise known as "bottles."
Electrons and other atomic structures have difficulty crossing a
magnetic field. By shaping the field, you can direct or contain them.
The shape of the field varies, but for the lightsaber effect, the
interior of the magnetic bottle will have to be about 3 feet long and
2 inches wide. This requires several focused, high-energy induction
coils to be mounted to a heavy iron core disk. The disk also serves as
a mount for the hilt.
One problem with the criticisms from a skeptics point of view (myself) is too many strawman the possibilities. For instance, yes, light would pass though, but the magnetic fields might react with each other. Light might only be present as a visual effect and the actual cutting taking place by some other means. In short, it may be possible to make a ‘light saber’ with some combination of technologies. Some which work together to repel light sabers from each other, other to cut materials, and yet others to create visual effects to guide the use.