Observation of stimulated emission of radiation by relativistic electrons in a spatially periodic transverse magnetic field

Abstract : Gain has been observed at 10.6 micrometers due to stimulated emission of radiation by relativistic electrons in a spatially periodic transverse magnetic field. The magnitude of the measured gain is close to the theoretical value for the stimulated emission process. The dependence of the gain on electron energy and current and on the polarization of the stimulating radiation are also consistent with the stimulated emission hypothesis. The results raise the possibility that this mechanism can be used in the development of a new class of tuneable high power lasers.