Chip-integrated monolayer graphene EO modulators. (A) Schematic illustration of a graphene-based optical modulator; (B) electrical field distribution of the hybrid graphene-silicon waveguide; (C) static EO response of the device [40]; (D) diagram of a high-speed EO modulator with a speed of 10 Gb s⁻¹; (E) measured and normalized EO S₂₁ responses; (F) optical eye diagrams at 8 and 10 Gb s⁻¹ modulation speeds [41]. (A)–(C) Adapted with permission from [40]. Copyright 2011, Springer Nature. (D)–(F) Adapted with permission from [41]. Copyright 2016, WILEY-VCH.