Jet & turbine engines provide abundant horsepower at the tailpipe[1]. A cursory search suggests typical jet fighter has one or two electric generators in 70...9

Jet & turbine engines provide abundant horsepower at the tailpipe[1]. A cursory search suggests typical jet fighter has one or two electric generators in 70...90kVA range that tap power off of the turbines' shaft - mostly meant to run the internal systems and any electronic payload [2]. While a 50kW laser needs much more electrical power than the 50kW optical output, you can conceivably recharge a bank of its (super)capacitors pretty fast from the 1x or 2x 70...90kVA source. I presume much higher power electric generators are a perfectly feasible upgrade, and just not installed presently for sake of space & weight savings. [1] there's no direct conversion as it depends on speed, but 266000 HP = 198 MegaWatt figure for a slow-flying Boeing 747 gives rough idea, as per https://www.quora.com/How-many-horsepower-is-a-Boeing-747-Jet https://www.quora.com/How-many-horsepower-is-a-Boeing-747-Je... [2] some fighters and most larger planes are also equipped with an independent APU - a self-contained power generator, also feeding off of the jet fuel