Pulsed mirror electron microscope: A fast near-surface imaging probe

A pulsed mirror electron microscope was developed for imaging laser-induced processes on the nanosecond time scale. Variations of the electronic structure of the surface are imaged. The evaporation or deposition of an atomic monolayer is readily detected. Pulsed mirror electron microscopy is an alternative technique to pulsed photoelectron microscopy for tracking chemical reactions. In addition, gas flow above the surface and laser-induced ablation of absorbing layers at the back surface of a dielectric can be probed, exploiting electron scattering and capacitive coupling, respectively. Presently, the space/time resolution is limited by the competition between electron shot noise and illumination aperture to 1 μm/5 ns. The illuminating electron pulses are supplied by a laser-driven robust ZrC-covered Re cathode. This device can be operated in a high vacuum of 10 −5 mbar either as a photo or a thermal electron emitter.