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Thegate-controllability of the Fermi-edge onset of interband absorptionin graphene can be utilized to modulate near-infrared radiation inthe telecommunication band. However, a high modulation efficiencyhas not been demonstrated to date, because of the small amount oflight absorption in graphene. Here, we demonstrate a ∼40% amplitudemodulation of 1.55 μm radiation with gated single-layer graphenethat is coupled with a silicon microring resonator. Both the qualityfactor and resonance wavelength of the silicon microring resonatorwere strongly modulated through gate tuning of the Fermi level ingraphene. These results promise an efficient electro-optic modulator,ideal for applications in large-scale on-chip optical interconnectsthat are compatible with complementary metal-oxide-semiconductor technology. [ABSTRACT FROM AUTHOR]

Gate-controllable transmission ofterahertz (THz) radiation makesgraphene a promising material for making high-speed THz wave modulators.However, to date, graphene-based THz modulators have exhibited onlysmall on/off ratios due to small THz absorption in single-layer graphene.Here we demonstrate a ∼50% amplitude modulation of THz waveswith gated single-layer graphene by the use of extraordinary transmissionthrough metallic ring apertures placed right above the graphene layer.The extraordinary transmission induced ∼7 times near-filedenhancement of THz absorption in graphene. These results promise complementarymetal–oxide–semiconductor compatible THz modulatorswith tailored operation frequencies, large on/off ratios, and highspeeds, ideal for applications in THz communications, imaging, andsensing. [ABSTRACT FROM AUTHOR]