title: Optical control of field-emission sites by femtosecond laser pulses.
abstract: We have investigated field-emission patterns from a clean tungsten tip apex induced by femtosecond laser pulses. Strongly asymmetric modulations of the field-emission intensity distributions are observed depending on the polarization of the light and the laser incidence direction relative to the azimuthal orientation of tip apex. In effect, we have realized an ultrafast pulsed field-emission source with site selectivity. Simulations of local fields on the tip apex and of electron emission patterns based on photoexcited nonequilibrium electron distributions explain our observations quantitatively.
authors.affiliation: Physik Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland. hirofumi@physik.uzh.ch
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Yanagisawa
authors.forename: Christian
authors.initials: C
authors.lastname: Hafner
authors.forename: Patrick
authors.initials: P
authors.lastname: Doná
authors.forename: Martin
authors.initials: M
authors.lastname: Klöckner
authors.forename: Dominik
authors.initials: D
authors.lastname: Leuenberger
authors.forename: Thomas
authors.initials: T
authors.lastname: Greber
authors.forename: Matthias
authors.initials: M
authors.lastname: Hengsberger
authors.forename: Jürg
authors.initials: J
authors.lastname: Osterwalder