title: Ultrafast active control of localized surface plasmon resonances in silicon bowtie antennas.
abstract: Localized surface plasmon polaritons (LSPPs) provide an efficient means of achieving extreme light concentration. In recent years, their active control has become a major aspiration of plasmonic research. Here, we demonstrate direct control of semiconductor bowtie antennas, enabling active excitation of LSPPs, at terahertz (THz) frequencies. We modify the LSPPs by ultrafast optical modulation of the free carrier density in the plasmonic structure itself, allowing for active control of the semiconductor antennas on picosecond timescales. Moreover, this control enables the manipulation of the field intensity enhancements in ranges of four orders of magnitude.
authors.affiliation: FOM Institute AMOLF Centre for Nanophotonics, HTC4, 5656AE Eindhoven, The Netherlands. a.berrier@amolf.nl
authors.forename: Audrey
authors.initials: A
authors.lastname: Berrier
authors.forename: Ronald
authors.initials: R
authors.lastname: Ulbricht
authors.forename: Mischa
authors.initials: M
authors.lastname: Bonn
authors.forename: Jaime Gómez
authors.initials: JG
authors.lastname: Rivas