Abstract: A graphene photodetector includes a first graphene absorption layer connected to first and second metal electrodes, the first and second metal electrodes defining a channel on the first graphene layer operating as a plasmonic waveguide, a gate dielectric layer interposed between the first graphene layer and a second graphene layer. The second graphene layer used for electrical gating and includes first and second gate electrodes proximate to the first and the second metal electrodes, respectively. The photodetector also includes a photonic dielectric waveguide with a planarized cladding underneath the gate dielectric layer, the first and second gate electrodes remaining interposed therebetween. The distance between the first and the second metal electrodes, defining the width of the channel cross-section, is between 100 nm and 600 nm, and the distance between the first and second gate electrodes is at least 60% of the distance between the first and second metal electrodes.