title: Polarisation-independent enhanced scattering by tailoring asymmetric plasmonic systems.
abstract: Polarised light provides an efficient way for dynamic control over local optical properties of nanoscale plasmonic structures. Yet many applications that utilise control over the plasmonic near-field would benefit if the plasmonic device maintained the same magnitude of optical response for all polarisations. Here we show that completely asymmetric nanostructures can be designed to exhibit a broadband polarisation-independent and enhanced optical response. We provide both analytical and experimental results on two sets of plasmonic trimer nanostructures consisting of unequal nanodisks/apertures with different gap spacing. We show that, at certain inter-particle separations, enhanced far-field cross sections are independent to the incident polarisation, while still demonstrating nontrivial near-field control.
authors.affiliation: The Blackett Laboratory, Department of Physics, Imperial College London, London SW7 2AZ, UK.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Geraci
authors.forename: Ben
authors.initials: B
authors.lastname: Hopkins
authors.forename: Andrey E
authors.initials: AE
authors.lastname: Miroshnichenko
authors.forename: Biniyam
authors.initials: B
authors.lastname: Erkihun
authors.forename: Dragomir N
authors.initials: DN
authors.lastname: Neshev
authors.forename: Yuri S
authors.initials: YS
authors.lastname: Kivshar
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Maier
authors.forename: Mohsen
authors.initials: M
authors.lastname: Rahmani