Flying laser weapons are coming.
The U.S. Air Force is on track to test its first airborne laser weapons by 2021. Lasers attached to fighter jets, drones, or even cargo planes will attack targets on the ground and in the air at the speed of light, making the assaults nearly impossible for enemy forces to dodge.
The Air Force has long had an interest in making laser weapons a reality. Lasers are ideal weapons for combat aircraft—in theory, anyhow—because the number of “shots” is limited only by the weapon’s power supply. Furthermore, each laser “shot” is relatively inexpensive compared to expensive missiles and other precision-guided munitions. Lasers also move at the speed of light, or 186,000 miles per second, making them impossible to evade.
Unfortunately, lasers are difficult to develop, particularly if you're trying to buld compact weapons with enough power to damage or destroy enemy objects. But now, according to Warrior Maven, the Air Force Research Lab thinks it can put laser weapons on aircraft starting in 2021. The service will start with larger C-130 and C-17 aircraft at first, then fighter-sized aircraft such as the F-15 and F-35 once technology inevitably shrinks the size of the weapon.
https://www.popularmechanics.com/military/research/a25383875/air-force-laser-weapons-test/