Abstract
It has been observed that the field emission of electrons from a micropoint carbon fibre cathode is accompanied by the emission of optical photons. Image intensifier techniques have been used both to record the visible spectrum of this radiation and to show that the dependence of its intensity on the applied voltage is consistent with it being electroluminescent in origin. The phenomenon has been qualitatively interpreted in terms of an emission mechanism involving a composite microregime consisting of a metallic-like substrate overlayed by a thin insulating medium.