Free-electron laser operation in the intermediate gain region

The modification induced on the well-known antisymmetric gain function of a free-electron laser when the gain coefficient g/sub 0/ ranges up to 10 is studied. Deviations from the linear regime for g/sub 0/>or=0.5 are presented, and a simple perturbative analysis which accounts remarkably well for the corrections to the linear gain formula even for g/sub 0/=10 is discussed. The effect of inhomogeneous broadening is also discussed.<
>