I don't think you understand the setup
Setup number 1 = Fighter is fleeing at mach 2 from a mach 5 missile
Setup number 2 = Ship is fleeing at 40mph from a mach 5 missile
Lasers moving at the speed of light is irrelevant, what matters is the engagement time and dwell time
engagement time = time it takes missile to hit target from 10km range (estimated range of laser effectiveness)
Dwell time = How long the laser needs to shine on a target before cooking it China's J-36 will be moving at mach 2 and blasting the missile with the defensive laser.
The ship will be doing the same. What this means is that China's J-36 will have around a 12 second window to blast the missile. The ship only has around 5 seconds before it impacts!
>THis may all be true, but the problems of heating dynamics remain. A laser cannot requires cooling times for both plane and ship because of heat, which limits the frequency it can be used.
The laser is only for defensive applications, its not going to be blasting for 10 minutes straight. It only needs around 3 seconds of dwell time to cook air to air missiles that are fired at it. The J-36 can handle this by using the heat from the laser to dump to heat into preheating its fuel.
>Dont tell me, tell the he navies of the world who have tried and failed to create lasers mounted on ships.
Because they don't work on sea - The laser is too weak, the target profile is designed to resist heat, and the engagement times are too short. While in a plane vs missile, the laser is stronger (less atmosphere and vapor), The target profile is vulnerable (Primary method to hit a stealth fighter is to use a heatseeking missile and not using a radar seeker), and engagement time is longer (Fighter is fleeing at mach 2)
Let me throw up some numbers for the 2 scenarios
1. Naval Ship vs. Inbound Hypersonic Missile
Missile: Mach 6 (1,950 m/s at sea level) carrying a UHTC ceramic matrix nose cone (2.5 cm thick) protecting an active millimeter-wave radar seeker.
Laser: 300 kW class Naval Solid-State Laser (SSL).
Engagement Envelope: Starts tracking at 15 km; laser fires at 10 km (optical line-of-sight window).
Time required to disable missile: 1.5s (tracking) + 3.8s (dwell) = 5.3 seconds
Time for Hypersonic missile to hit : 5.12 seconds
2. J-36 vs. Air to Air Missile
Missile: Mach 5 (1,475 m/s at 35,000 ft) tail-chasing the jet. Carrying a toughened Sapphire/Yttria optical dome covering a dual-band Infrared Search & Track (IRST) seeker.
Fighter Jet: J-36 fleeing at Mach 2 (590 m/s at 35,000 ft).
Laser: 100 kW class internal pulse-burst laser.
Engagement Envelope: Laser fires rearward at 10 km distance.
Time required to disable missile: 1.2s (tracking) + 1.6s (dwell) = 2.8seconds.
Total time before impact: Because the J-36 is fleeing at Mach 2, it takes the missile 11.3 seconds to catch up and hit the J-36.
Conclusion
The ship with a 300kw laser, will take 5.3 seconds to disable a hypersonic anti ship missile. The hypersonic antiship missile will take 5.12 seconds to hit the ship.
The J-36 with a 100kw laser, will take 2.8 seconds to disable a Air to Air Infrared missile. The air to air missile will take 11.3 seconds to hit the J-36.