Optical guiding and superradiance effects in free electron lasers

Efficiency enhancement in FEL under optical guiding condition and generation of short power electromagnetic pulse due to the superradiation processes are investigated The paper is concerned with radiation of ensembles of electron-oscillators in free space (see also [1–8]). Processes of two types are investigated: 1) the amplification and canalization of radiation along the electron waveguide formed by high-current electron beams; 2) the superradiance of the short electron pulse (clusters) that are essentially moving active resonators.