One of the most iconic aspects of the Star Wars saga is the preferred weapon of the Jedi & the Sith- the lightsaber. The beauty of science fiction is that the elements of the story don't necessarily have to be based in current scientific understanding.
Although we don't have the technology to develop a working lightsaber, that hasn't stopped people from imagining ways to bring this legendary melee weapon to life. Here's a post I made in 2010 about building this deadly energy blade:
The Monkey Buddha Archives:
Here's a video from the excellent series FW: Thinking that also explores the possibility of building a lightsaber. The lightsabers in the movies are plasma weapons, however, not lasers.
Since I'm talking about lightsaber construction, I have to include my own crude schematics that I drew as a high school student, back in 1996. I knew just enough about physics to let my mind go wild thinking about how to solve this perennial problem in sci-fi tech.
In reality, I didn't know what the hell I was doing, but it was fun to think about...