Phenomenon of anomalous diffraction radiation in the metal-dielectric grating

Conditions for occurrences of a diffraction radiation (DR) exclusively into the dielectric of metal-dielectric grating (we have named this phenomenon an anomalous DR or ADR) are shown and analyzed. Contrary to the Cerenkov radiation, an ADR may occur at ultra low electron velocities (/spl beta//spl Lt/1//spl radic//spl epsi/). Electromagnetic field, energy density and other characteristics of the ADR are found as the exact solution of the strict mathematical task. A number of ADR characteristics have been calculated. The use of the ADR phenomenon is suggested for the miniaturization of diffraction electronic devices, e.g. in the design of semiconductor oscillators.