That better be pure, uncut oregano or I'll callin' the space cops.
Star Wars took a little bit from so many sources dating back to the legends and archetypes of ancient Greece that yeah, DUNE is probably likely given the examples you mentioned. SW is hardly original in any way shape or form except in the ways it took classic weaponry and other references and gave them a sophisticated, technologically-advanced sci-fi/fantasy twist. In the end a lightsaber is just a really, really badass and original concept of a traditional warrior's sword.
But there's nothing wrong with being unoriginal so long as the movie or TV show is profoundly entertaining and has a lasting, positive impact, and SW definitely did both of those in spades.