Wendy's does it like that, and Burger King has a little conveyor belt and the patty gets blasted with fire as it goes through.

i am eager to see the new laser cooked burgers. whenever they invent them

Which is kinda funny since I think that's kinda how Hamburg steaks were often cooked historically. The grill was used for hamburgers once it became more common since the actual oven grill thing was too expensive or complex.