Future concept for compact FEL using a field emission micro-cathode

The paper proposes the concept of the compact free electron laser using Smith–Purcell radiation and field emitters, and describes preliminary experiments associated with the generation of a modulation beam directly from the cathodes. The emission characteristics of the GaAs emitter designed for the Gunn effect strongly suggest the generation of a modulation beam. The illumination of a pulse laser on a p-type emitter also generates a modulation beam. However, for a high-frequency modulation beam, the suppression of the diffusion of the photogenerated carriers in the emitter is necessary.