Once read a theoretical on how could a light saber be built.
The first concern was energy source. It implied developing an entirely new concept of super compact, super dense, super conductor based, nano scale batteries, capable of stories several gigawatts of power.
The concern was insulation and protection for the wielder. This demanded an entire class of materials, probably new kinds of ceramics, reinforced at the molecular level to withstand the pressure...
Of the third concern wich was forming and projecting the blade itself, for which was proposed a magnetic field contained, super condensed plasma beam, exuded through a series of nano tubes that would extend from the handles by the sheer pressure of the plasma.
So, in all good faith, sonething to aspire in the 500 or 600 years.
The original lightsaber had an external battery connected by a wire. Lightsaber technology evolved over thousands of years until they became what we know today.
The first concern was energy source. It implied developing an entirely new concept of super compact, super dense, super conductor based, nano scale batteries, capable of stories several gigawatts of power.