Fig. 3
From: Towards integrated tunable all-silicon free-electron light sources
Spectrally, spatially, and polarization-resolved modified-SEM cathodoluminescence measurement setup. a A modified SEM generates an electron beam impinging on a nanograting at a grazing angle. A Faraday cup, mounted on the sample holder, is used to record the electron beam current I. A microscope objective collects and couples out the radiation induced by free electrons to a set of free space optics. b Peak intensity as a function of the polarization angle. \(\alpha = 0\) corresponds to the direction of electron beam propagation. The dashed line shows an affine fit in \(\cos ^2\alpha\). c Scanning-electron micrographs of 278 and 139 nm (inset) silicon nanogratings. Scale bar is 1 µm
