Cerenkov lasers

Cerenkov lasers, which are driven by a relativistic electron beam, may be based either upon dielectric waveguide resonators or gas-filled Fabry-Perot resonators. When the beam energy exceeds the Cerenkov threshold, stimulated Cerenkov radiation causes beam bunching, and energy can be extracted at a wavelength determined by the beam and the resonator characteristics. Devices have already been operated successfully in the lower- and submillimeter regime. The possibility of far-infrared operation will be discussed in this paper.