Abstract

The absence of a medium other than an electron beam in the tree-electron laser (FEL) provides advantages over conventional laser systems. Emission wavelength is not determined by transitions between fixed energy levels, which means that the same interaction mechanism can be used from microwaves to x-rays. A given FEL oscillator may be tuned over a decade wavelength interval. In the absence of a medium, the problems of material heating and damage are avoided, so that FEL average powers as high as megawatts should be possible. In conventional lasers at short wavelengths, the pump power density must become large, varying as λ^-6, to maintain an inverted population as the spontaneous emission time decreases. This problem does not exist for the FEL.

© 1992 Optical Society of America