A Femtosecond Nanometer Free Electron Source

Hommelhoff, Peter; Sortais, Yvan; Aghajani-Talesh, Anoush; Kasevich, Mark A.

A Femtosecond Nanometer Free Electron Source

Authors

Hommelhoff, Peter

Sortais, Yvan

Aghajani-Talesh, Anoush

Kasevich, Mark A.

Description

We report a source of free electron pulses based on a field emission tip irradiated by a low-power femtosecond laser. The electron pulses are shorter than 70 fs and originate from a tip with an emission area diameter down to 2 nm. Depending on the operating regime we observe either photofield emission or optical field emission with up to 200 electrons per pulse at a repetition rate of 1 GHz. This pulsed electron emitter, triggered by a femtosecond oscillator, could serve as an efficient source for time-resolved electron interferometry, for time-resolved nanometric imaging and for synchrotrons.