General Energy Weapons Discussion Thread

Glock is a real company, too ^^

It has already been answered who made the energy weapons, additionally the Gatling Laser in Fallout 1/2 was made by Heckler & Koch. There's also the Yuma Flats Energy Consortium that made the pulse rifle and pistol in Fallout 2.
It's not just military either, the laser pistol in Fallout 1/2 is specifically a civilian model, so we know that energy weapons were, to some degree, available to civilians as well.
The energy weapons in Fallout 1/2 and New Vegas kinda overlap, but New Vegas also has the Fallout 3 energy weapons. So the laser pistol, plasma pistol, laser rifle, and plasma rifle are from Fallout 3, but the plasma defender and plasma caster are supposed to be the ones from the classics. Gatling laser looks too different as well.
As for why they look cheap, well, that's mostly down to design choices of the arts department. Particularly the plasma rifle and pistol have this rather fragile pulp scifi look to them because Bethesda really went for the 1950's look, and that carried over. The laser rifle is actually one of the few designs I really like from the 3D games, it looks rugged and really what a real life laser rifle might look like.