Laser weapons as such would be "hard" sci-fi precisely because we have working prototypes.

Basically: hard sci-fi: we have concepts and understand how to apply them, but it may not be practical (e.g. Orion drive) soft sci-fi: we have concepts but no idea how to apply them (e.g. antimatter power plants) science fantasy: anything goes, technobabble as a veeneer for lack of science

But yes, writing convincing science fiction is hard.