Observation of coherent Cerenkov radiation at optical frequencies

Abstract
Coherent Cerenkov radiation at 0.532 μm was observed from an optically bunched relativistic electron beam. Bunching was induced by means of the inverse Cerenkov effect wherein, to achieve phase matching, light at 1.06 μm from a Nd:YAG laser intersected the electron beam at the Cerenkov angle within a gaseous medium. The pressure dependence of this radiation was verified.