title: Optical Activation of Germanium Plasmonic Antennas in the Mid-Infrared.
abstract: Impulsive interband excitation with femtosecond near-infrared pulses establishes a plasma response in intrinsic germanium structures fabricated on a silicon substrate. This direct approach activates the plasmonic resonance of the Ge structures and enables their use as optical antennas up to the mid-infrared spectral range. The optical switching lasts for hundreds of picoseconds until charge recombination redshifts the plasma frequency. The full behavior of the structures is modeled by the electrodynamic response established by an electron-hole plasma in a regular array of antennas.
authors: Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany.
authors: Marco P
authors: MP
authors: Fischer
authors: Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany.
authors: Christian
authors: C
authors: Schmidt
authors: Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Emilie
authors: E
authors: Sakat
authors: Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany.
authors: Johannes
authors: J
authors: Stock
authors: School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT, United Kingdom.
authors: Antonio
authors: A
authors: Samarelli
authors: L-NESS, Dipartimento di Fisica del Politecnico di Milano, Via Anzani 42, 22100 Como, Italy.
authors: Jacopo
authors: J
authors: Frigerio
authors: Department of Physics, Sapienza University of Rome, Rome 00185, Italy.
authors: Michele
authors: M
authors: Ortolani
authors: School of Engineering, University of Glasgow, Rankine Building, Oakfield Avenue, Glasgow G12 8LT, United Kingdom.
authors: Douglas J
authors: DJ
authors: Paul
authors: L-NESS, Dipartimento di Fisica del Politecnico di Milano, Via Anzani 42, 22100 Como, Italy.
authors: Giovanni
authors: G
authors: Isella
authors: Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany.
authors: Alfred
authors: A
authors: Leitenstorfer
authors: Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
authors: Paolo
authors: P
authors: Biagioni
authors: Department of Physics and Center for Applied Photonics, University of Konstanz, D-78457 Konstanz, Germany.
authors: Daniele
authors: D
authors: Brida