Keep in mind that they would likely not be actually made of lasers as this would be largely impractical. It is more feasible that it would be made out of a super-heated plasma.
Some important potential technological advancements would be:
1) increased knowledge of magnetic fields and their mechanisms (necessary to control the plasma)
-Other purposes: Magnetic fields would be a necessary part of any endeavors to colonize and terraform other planets (i.e. mars who has lost most of its magnetic field)
2) Better batteries (likely going to be composed of carbon nanotubes. The lightsaber would require a large power source)
-Other purposes: This would have major industrial purposes given the broad use of batteries today. Carbon nanotube based batteries are millions of times as powerful as the standard voltaic batteries that we use. This could contribute to further miniturization of technology & components (i.e. in computers the power source would occupy less space, allowing more room for hardware).
Here's more info on the topic:
apparently there's actually a white house petition on it right now