We studied by broad-band pump-probe spectroscopy the ultrafast optical response of thin copper films covered by a monolayer of graphene. It is demonstrated that graphene protection does not alter the thermo-modulational nonlinearity of copper in the whole visible range. Also, we provide a quantitative validation of a theoretical model for this optical nonlinearity, derived from a semiclassical description of electron thermalization dynamics and subsequent modulation of copper dielectric function from 450 to 700 nm wavelength. Our results extend to the nonlinear domain the capability of graphene-protected copper nanolayers to serve as a low cost optical grade material, with major potential impact on nonlinear plasmonics and metamaterials.

Ultrafast Spectroscopy of Graphene-Protected Thin Copper Films

POGNA, EVA ARIANNA AURELIA;DAL CONTE, STEFANO;SOAVI, GIANCARLO;LONGHI, STEFANO;CERULLO, GIULIO NICOLA;DELLA VALLE, GIUSEPPE
2016-01-01

Abstract

We studied by broad-band pump-probe spectroscopy the ultrafast optical response of thin copper films covered by a monolayer of graphene. It is demonstrated that graphene protection does not alter the thermo-modulational nonlinearity of copper in the whole visible range. Also, we provide a quantitative validation of a theoretical model for this optical nonlinearity, derived from a semiclassical description of electron thermalization dynamics and subsequent modulation of copper dielectric function from 450 to 700 nm wavelength. Our results extend to the nonlinear domain the capability of graphene-protected copper nanolayers to serve as a low cost optical grade material, with major potential impact on nonlinear plasmonics and metamaterials.
graphene; hot electrons; metal optics; nonlinear optics; ultrafast spectroscopy; Electronic, Optical and Magnetic Materials; Atomic and Molecular Physics, and Optics; Biotechnology; Electrical and Electronic Engineering
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11311/1001767
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