Open AccessTHz saturable absorption in turbostratic multilayer graphene on silicon carbide
Author(s) -
Federica Bianco,
Vaidotas Mišeikis,
Domenica Convertino,
J. Xu,
Fabrizio Castellano,
Harvey E. Beere,
D. A. Ritchie,
Miriam S. Vitiello,
Alessandro Tredicucci,
Camilla Coletti
Publication year - 2015
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.23.011632
Subject(s) - graphene , materials science , saturable absorption , silicon carbide , terahertz radiation , optics , optoelectronics , silicon , absorption (acoustics) , laser , nanotechnology , fiber laser , wavelength , physics , metallurgy , composite material
We investigated the room-temperature Terahertz (THz) response as saturable absorber of turbostratic multilayer graphene grown on the carbon-face of silicon carbide. By employing an open-aperture z-scan method and a 2.9 THz quantum cascade laser as source, a 10% enhancement of transparency is observed. The saturation intensity is several W/cm2, mostly attributed to the Pauli blocking effect in the intrinsic graphene layers. A visible increase of the modulation depth as a function of the number of graphene sheets was recorded as consequence of the low nonsaturable losses. The latter in turn revealed that crystalline disorder is the main limitation to larger modulations, demonstrating that the THz nonlinear absorption properties of turbostratic graphene can be engineered via a proper control of the crystalline disorder and the layers number.