I think, the problem with the laser sword is not, it doesn't exist, but it doesn't make sence after all.
In all equipment integrated into the game there is a kind of explanation, how this gear could work and why it works the way it does. If you take the plasma blade for example, it is not a blade made out of plasma (cause that would be impossible cause of plasma being liquid) nor lets say, ionic plasma formed to a blade through a magnetic field (a pseudo explanation, but still, what good would a liquid blade do, that a solid blade dont?), but more like a plasma contact mine, once attached glued to the uniform and releasing plasma to the surface of your amour in a vacuum. There is an explanation, how it works, and it is imaginable to be useful against heavy amour, so there is a reason, why it exists.
The concept of a laser sword doesn't meet both requirements. There is no explanation how this could exist, because laser is light, that wouldn't stop shining at the end of the blade and because of it being light, one of the most important things, you would have to be able to do with a sword: defending ; wouldn't be doable. First there would have to be a pseudo explanation explaining the existence of a laser sword, before I'd like to see this weapon integrated in this game. And, well, there would have to be an explanation, too, why a laser rifle empties a df-ammo in some minutes autofire, while a laser sword should be turned on all the time without using ammunition.