I believe if one was to truly procure a shark with a 'fricken' laser beam on its head, it would require a willing shark, or unwilling-if your into that,-a scalpel, of course the required laser equipment, and a plastic surgeon to use the aforementioned scalpel.
How would you power it ? I suppose you could install a motor that runs off of the motion of the shark as it swims, and power the laser indefinitely. You would have to worry about specular reflection back into the lasing cavity though - you really do not want to have to corner this pissed off shark anywhere and have to install a back-up diode or anyhting....it should be a install once and swim like hell to get away LOL