Z.L. Sámson

Metamaterial electro-optic switch of nanoscale thickness

NanoBioScience Lab, Istituto Italiano di Tecnologia, Via Morego 30, I16163 Genova, Italy andBIONEM Lab, University of Magna Graecia, viale Europa, I88100 Catanzaro, Italy(Dated: December 21, 2009)Combining metamaterials with functional media brings a new dimension to their performance.Here we demonstrate substantial resonance frequency tuning in a photonic metamaterial hybridizedwith an electrically/optically switchable chalcogenide glass. The transition between amorphousand crystalline forms brings about a 10% shift in the near-infrared resonance wavelength of anasymmetric split-ring array, providing transmission modulation functionality with a contrast ratioof 4:1 in a device of sub-wavelength thickness.We demonstrate an innovative concept for nanoscale electro-optic switching. It exploits the frequency shift of a narrow-band Fano resonance mode in a plasmonic planar metamaterial induced by a change in the dielectric properties of an adjacent chalcogenide glass layer. An electrically stimulated transition between amorphous and crystalline forms of the glass brings about a 150 nm shift in the near-infrared resonance providing transmission modulation with a contrast ratio of 4:1 in a device of subwavelength thickness.

Femtosecond surface plasmon pulse propagation.

We analyze ultrafast surface plasmon-polariton pulse reshaping effects and nonlinear propagation modes for metal/dielectric plasmon waveguides. It is found that group velocity and loss dispersion effects can substantially modify both pulse duration (broadening/narrowing) and intensity decay (acceleration/retardation) by as much as several tens of percentage points in the short-pulse regime and that metallic nonlinearities alone may support soliton, self-focusing, and self-compressing modes.

Femtosecond active plasmonics: ultrafast control of surface plasmon propagation

Excitation of an aluminium/dielectric plasmonic waveguide with 200 fs optical pulses leads to the transient modulation of surface plasmon-polariton signals propagating in the waveguide. We show that by tuning the excitation wavelength to aluminium’s interband absorption peak at ∼1.5 eV, a modulation depth of more than 35% can be achieved at an excitation fluence of 13 mJ cm −2 . ‘Fast’ (femtosecond) and ‘slow’ (picosecond) modulation response components

Active plasmonics: Current status

Techniques for active modulation and control of plasmonic signals in future highly-integrated nanophotonic devices have advanced rapidly in recent years, with recent innovations extending performance limits into the technologically relevant terahertz frequency and femtojoule-per-bit switching energy domains.

Chalcogenide Glass Metamaterial Optical Switch

The technology behind rewritable optical disks offers a new switching paradigm for metamaterials. A switch comprising resonant plasmonic metamaterial and electro-optic chalcogenide glass layers provides 75% optical transmission modulation in a device of sub-wavelength thickness.

Propagation and active control of femtosecond plasmon pulses

Here we report on the ultrafast modulation of propagating fs SPP signal via direct optical excitation of the metal component of an aluminium/silica waveguide and investigate spectral dependence of the effect and its kinetics. We also analyse numerically the nonlinear SPP pulse propagation regimes, including self-focusing, pulse compression and solitons, supported by the nonlinearity of the metal component of the waveguide.

Ultrafast active plasmonics: transmission and control of femtosecond plasmon signals

We report that femtosecond surface plasmon polariton pulses can propagate along a metal-dielectric waveguide and that they can be modulated on the femtosecond timescale by direct ultrafast optical excitation of the metal, thereby offering unprecedented terahertz plasmonic bandwidth - a key missing component in the development of surface plasmons as information carriers for next generation nanophotonic devices.