title: A resonant scanning dipole-antenna probe for enhanced nanoscale imaging.
abstract: We present a scanning antenna probe that provides 35 nm optical hotspots with a 16-fold excitation enhancement. A resonant optical antenna, tuned to operation in the visible, is carved into the aluminum-coated scanning probe. The antenna resonances, field localization, excitation, and polarization response are probed in the near-field by scanning over single fluorescent nanobeads. At the same time, the distance-dependent coupling of the emission to the antenna mode is mapped. Good agreement with theory is obtained. The presented scanning antenna approach is useful for both nanoscale plasmonic mode imaging and (bio)imaging.
authors.affiliation: ICFO-Institut de Ciencies Fotoniques , Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.
authors.forename: Lars
authors.initials: L
authors.lastname: Neumann
authors.forename: Jorick
authors.initials: J
authors.lastname: van 't Oever
authors.forename: Niek F
authors.initials: NF
authors.lastname: van Hulst