This question already has an answer here:
In the Wookiepedia article on blaster technology, lasers - in the context of true electromagnetic beams - are mentioned to be archaic, suggesting they existed in Star Wars military history. The Wookiepedia article on lasers, however, are in the context of being interchangeable terminology with blasters, and so do not refer to true lasers.
What records of true laser weaponry are there?
Legends answer preferred, since the article that contains the references are from Legends.