The emission times of laser-triggered electrons from a sharp tungsten tip are directly characterized under ultrafast, near-infrared laser excitation at Keldysh parameters 6.6<γ<19.1. Emission delays up to 10 fs are observed, which are inferred from the energy gain of photoelectrons emitted into a synchronously driven microwave cavity. ~ fs timing resolution is achieved in a configuration capable of measuring timing shifts up to 55 ps. The technique can also be used to measure the microwave phase inside the cavity with a precision below 70 fs upon the energy resolved detection of a single electron.
@article{arxiv.1503.05842,
title = {Ultrafast time resolved photo-electric emission},
author = {Thomas Juffmann and Brannon B. Klopfer and Gunnar E. Skulason and Catherine Kealhofer and Fan Xiao and Seth M. Foreman and Mark A. Kasevich},
journal= {arXiv preprint arXiv:1503.05842},
year = {2016}
}