"On a fighter although it is a turbo jet" - I think generally all fighter engines nowadays are turbofans, but with a lower bypass ratio than airliner engines.
Originally civil & military engines were basically the same thing, RR Avon/Conway/Spey, etc but then they went their own ways with high bypass for civil use where speeds are lower, economy very important and engine diameter not so critical and low bypass for military use where high speed is important, economy less so and smaller diameters required.