  Photoelectron field emission, induced by femtosecond laser pulses focused on
metallic nanotips, provides spatially coherent and temporally short electron
pulses. The properties of the photoelectron yield give insight into both the
material properties of the nanostructure and the exciting laser focus.
Ultralong nanoribbons, grown as a single crystal attached to a metallic taper,
are sources of electron field emission that have not yet been characterized. In
this report, photoemission from gold nanoribbon samples is studied and compared
to emission from tungsten and gold tips. We observe that the emission from
sharp tips generally depends on one transverse component of the exciting laser
field, while the emission of a blunted nanoribbon is found to be sensitive to
both components. We propose that this property makes photoemission from
nanoribbons a candidate for position-sensitive detection of the longitudinal
field component in a tightly focused beam.
