title: THz bandwidth optical switching with carbon nanotube metamaterial.
abstract: We provide the first demonstration of exceptional light-with-light optical switching performance of a carbon nanotube metamaterial - a hybrid nanostructure of a plasmonic metamaterial with semiconducting single-walled carbon nanotubes. A modulation depth of 10% in the near-IR with sub-500 fs response time is achieved with a pump fluence of just 10 μJ/cm², which is an order of magnitude lower than in previously reported artificial nanostructures. The improved switching characteristics of the carbon nanotube metamaterial are defined by an excitonic nonlinearity of carbon nanotubes resonantly enhanced by a concentration of local fields in the metamaterial. Since the spectral position of the excitonic response and metamaterial plasmonic resonance can be adjusted by using carbon nanotubes of different diameter and scaling of the metamaterial design, the giant nonlinear response of the hybrid metamaterial - in principle - can be engineered to cover the entire second and third telecom windows, from O- to U-band.
authors.affiliation: Optoelectronics Research Centre & Centre for photonic Metamaterials, University of Southampton, Southampton, SO17 1BJ, UK. aen@orc.soton.ac.uk
authors.forename: Andrey E
authors.initials: AE
authors.lastname: Nikolaenko
authors.forename: Nikitas
authors.initials: N
authors.lastname: Papasimakis
authors.forename: Arkadi
authors.initials: A
authors.lastname: Chipouline
authors.forename: Francesco
authors.initials: F
authors.lastname: De Angelis
authors.forename: Enzo
authors.initials: E
authors.lastname: Di Fabrizio
authors.forename: Nikolay I
authors.initials: NI
authors.lastname: Zheludev
mesh_terms: D004867:Equipment Design; D019544:Equipment Failure Analysis; D008027:Light; D008422:Materials Testing; D037742:Nanotubes, Carbon / Q000737:chemistry* / Q000528:radiation effects*; D012031:Refractometry / Q000295:instrumentation*; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D055053:Terahertz Radiation
chemical_list: D037742:Nanotubes, Carbon