Integrated photonics meet electron microscopy

A ring resonator. Credit: Alex Mehler (Woogieworks) - Scientists in Switzerland and Germany have achieved efficient electron-beam modulation using integrated photonics - circuits that guide light on a chip. The experiments could lead to entirely new quantum measurement schemes in electron microscopy. The transmission electron microscope (TEM) can image molecular structures at the atomic scale by using electrons instead of light, and has revolutionized materials science and structural biology. The past decade has seen a lot of interest in combining electron microscopy with optical excitations, trying, for example, to control and manipulate the electron beam by light. But a major challenge has been the rather weak interaction of propagating electrons with photons. In a new study, researchers have successfully demonstrated extremely efficient electron beam modulation using integrated photonic microresonators.