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.

Abstract: A segmented optical modulator includes: a waveguide where electromagnetic radiation to be modulated is adapted to travel along a travelling direction; between 2 and 30 modulating segments each including: first and second layers of graphene, a portion of the first layer of graphene overlaying a portion of the second and the first and second layers of graphene overlaying a portion of the waveguide; a dielectric layer interposed between the first and second layers of graphene, the dielectric layer having a thickness between 6 nm EOT and 15 nm EOT; a first metal electrode in contact with the first layer of graphene; a second metal electrode in contact with the second layer of graphene; the distance between the first and second electrodes being between 650 nm and 1500 nm; the length of each segment in the travelling direction being between 10 micrometers and 60 micrometers.