Laser weapons on a ship are doable, albeit they are a work very much in progress.
The same sort of weapon on a fighter won't be a BVR type requirement, but a "dogfighting" requirement that yields a gun with a much faster bullet hitting ... what? ... on the target. If and only if the power/heat/weight problem is resolved.
F-35 has a host of far more pressing issues to address before advancing into the Starfighter II role. The original Starfighter was the F-104.
Slight topic drift about lasers as airborne weapons.
I had heard about this program's demise, but thanks to that link I can put it in my timeline. (Scientist's rant on military laser funding ... axe to grind is funding ... but his points on the challenges are well made).
But by 2009, the
Air Force finally faced facts, realizing that its Airborne Laser still wouldn’t fit into a Boeing 747. Nor could it produce anywhere near the required power to destroy ballistic missiles.
BFI has been dead longer than I had supposed. You have no idea how many Ballistic Missile Defense meetings and conferences I attended where we got worn out by USAF enthusiasm for the North Korean ballistic missiles being knocked out by a 747 carrying a laser in the boost phase.
Thankful that is over. The JSF is now the high tech money sink.