In this work, we take advantage of the strong temperature modulation of the graphene conductivity to propose an all-optical technique of excitation and manipulation of plasmons in graphene and thin metallic films, via the spatial patterning of the temperature of electrons in a graphene film, which can diffract a probe beam and directly excite plasmons.
Additionally, we demonstrate the ability of graphene, thin metals films, and graphene-metal hybrid systems to undergo photothermal optical modulation with depth as large as >70% over a wide spectral range extending from the visible to the terahertz spectral domains. We envision the use of ultrafast pump laser pulses to raise the electron temperature of graphene during a picosecond timescale in which its mid-infrared plasmon resonances undergo dramatic shifts and broadenings, while visible and near-infrared plasmons in neighbouring metal films are severely attenuated by the presence of hot graphene electrons.
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