Optical control of field-emission sites by femtosecond laser pulses.
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.
Yanagisawa
Hirofumi
H
Physik Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland. hirofumi@physik.uzh.ch
Hafner
Christian
C
Doná
Patrick
P
Klöckner
Martin
M
Leuenberger
Dominik
D
Greber
Thomas
T
Hengsberger
Matthias
M
Osterwalder
Jürg
J