Controlling Electrons with Light
When a laser pulse is focused tightly onto the apex of a metallic tip with nanometer sharpness, the maximal intensity of light appears on the shadow side with respect to the laser exposure. The intense light induces electron emission, and thereby the emission pattern becomes strongly asymmetric between the shadow and directly exposed sides to the light, as shown in the figure where the emission currents are imaged on a two-dimensional detector. This phenomenon can be used to control electron-emission sites on the scale of a few tens of nanometers. An electron source with optical control of spatiotemporal emission properties is thus established which opens new opportunities for addressing fundamental properties of electron waves, or for new directions in electron holography.
