Measurement of smith-purcell radiation spectrum from a photonic crystal

When the electron beam of high energy (150MeV) passes near the surface of a photonic crystal at uniform velocity, optical radiation in a millimeter wave region is observed. It turns out that this light is converted from the evanescent wave emitted by the electrons into propagating waves through the photonic band modes in resonance. Since the previous measurements showed that a radiation peak appeared in out of region above the mechanism, the experiments for specifying the origin of this radiation was conducted. It was observed that intensity of the radiation increased for 3D photonic crystal of double layers. (author)