Fig. 1
From: Towards integrated tunable all-silicon free-electron light sources
Broadly tunable radiation from all-silicon nanogratings. a An electron emitter (in vacuum) generates a beam of electrons traveling at a grazing angle to an all-silicon nanograting, thus generating tunable radiation that follows the SP wavelength-angle equation. In our current experimental setup (see Fig. 3), the electron emitter consists of the electron gun of a scanning electron microscope (SEM). b In future devices, the emitter could be integrated onto a silicon chip (see Fig. 4) with, for instance, (gated) silicon field emitter arrays. We discuss the compatibility of this proposed device with conventional fabrication techniques and CMOS-compatibility in the Discussion section and in the Supplementary Note 9
