title: Bridging the Gap between Dielectric Nanophotonics and the Visible Regime with Effectively Lossless Gallium Phosphide Antennas.
abstract: We present all-dielectric gallium phosphide (GaP) nanoantennas as an efficient nanophotonic platform for surface-enhanced second harmonic generation (SHG) and fluorescence (SEF), showing negligible losses in the visible range. Employing single GaP nanodisks, we observe an increase of more than 3 orders of magnitude in the SHG conversion signal in comparison with the bulk. This constitutes an SHG efficiency as large as 0.0002%, which is to the best of our knowledge the highest yet achieved value for a single nano-object in the optical region. Furthermore, we show that GaP dimers with 35 nm gap can enhance up to 3600 times the fluorescence emission of dyes located in the gap of the nanoantenna. This is accomplished by a fluorescence lifetime reduction of at least 22 times, accompanied by a high-intensity field confinement in the gap region. These results open new avenues for low-loss nanophotonics in the optical regime.
authors.affiliation: The Blackett Laboratory , Department of Physics, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Javier
authors.identifier: 0000-0002-1965-5424
authors.initials: J
authors.lastname: Cambiasso
authors.affiliation: The Blackett Laboratory , Department of Physics, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Gustavo
authors.identifier: 0000-0002-1637-9524
authors.initials: G
authors.lastname: Grinblat
authors.affiliation: The Blackett Laboratory , Department of Physics, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Yi
authors.initials: Y
authors.lastname: Li
authors.affiliation: The Blackett Laboratory , Department of Physics, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Aliaksandra
authors.identifier: 0000-0003-1056-5729
authors.initials: A
authors.lastname: Rakovich
authors.affiliation: The Blackett Laboratory , Department of Physics, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Cortés
authors.affiliation: The Blackett Laboratory , Department of Physics, Imperial College London, London, SW7 2AZ, United Kingdom.
authors.forename: Stefan A
authors.initials: SA
authors.lastname: Maier
keywords: Gallium phosphide; Purcell effect; dielectric nanoantennas; fluorescence enhancement; second harmonic generation