Weird - Northrop's 1985 'Pre-combustion integrated Ram airbreathing laser'

[flateric]

"The present invention provides a Ram airbreathing laser adapted to use with an aircraft which operates primarily in the Mach 3 to Mach 6 regime. Valves, or gates, are provided in the propulsive flow path and the auxiliary flow path for laser in a manner such that the air entering the aircraft..."

 

[mz]

interesting, an air breathing chemical laser?

 

[DSE]

I've seen several AIAA papers with respect to this from the late 80's, iirc. There are also concepts to incorporate such in a scramjet and then use the laser power for ignition/flameholding. The key issue I see is having a uniform enough flowfield in the gas used for the laser cavity to have sufficient beam quality/power extraction. Typically one strives for density fluctuations (del rho/rho) on the order of 10^-3 or smaller. For a typical scramjet flowfield non-uniformities are many orders of magnitude greater than this.