title: Robustness of plasmon phased array nanoantennas to disorder.
abstract: We present cathodoluminescence experiments that quantify the response of plasmonic Yagi-Uda antennas fabricated on one-dimensional silicon nitride waveguides as function of electron beam excitation position and emission wavelength. At the near-infrared antenna design wavelength cathodoluminescence signal robustly is strongest when exciting the antenna at the reflector element. Yet at just slightly shorter wavelengths the signal is highly variable from antenna to antenna and wavelength to wavelength. Hypothesizing that fabrication randomness is at play, we analyze the resilience of plasmon Yagi-Uda antennas to variations in element size of just 5 nm. While in our calculations the appearance of directivity is robust, both the obtained highest directivity and the wavelength at which it occurs vary markedly between realizations. The calculated local density of states is invariably high at the reflector for the design wavelength, but varies dramatically in spatial distribution for shorter wavelengths, consistent with the cathodoluminescence experiments.
authors.affiliation: Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, NL-1098XG Amsterdam, The Netherlands.
authors.forename: Felipe Bernal
authors.initials: FB
authors.lastname: Arango
authors.affiliation: Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, NL-1098XG Amsterdam, The Netherlands.
authors.forename: Rutger
authors.initials: R
authors.lastname: Thijssen
authors.affiliation: Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, NL-1098XG Amsterdam, The Netherlands.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Brenny
authors.affiliation: Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, NL-1098XG Amsterdam, The Netherlands.
authors.forename: Toon
authors.initials: T
authors.lastname: Coenen
authors.affiliation: Center for Nanophotonics, FOM Institute AMOLF, Science Park 104, NL-1098XG Amsterdam, The Netherlands.
authors.forename: A Femius
authors.initials: AF
authors.lastname: Koenderink