A structure of electro-absorption hybrid plasmonic modulator using silver nano-ribbon

In this paper, an electro-absorption modulator based on a hybrid plasmonic structure is designed and analyzed for wavelengths ranging from 1300 to 1800 nm and chemical potentials ranging from 0 to 0.65 eV for graphene. This modulator has a high modulation depth (19.9 dB/µm) in the broad wavelength range of 1300–1800 nm. The proposed modulator comprises three graphene layers and two Hexagonal Boron Nitride (h-BN) layers. Silver nano-ribbons are placed on the structure and inside the silicon layer. The silver nano-ribbons create a spatially confined plasmonic mode along its edge. The edge is covered by graphene sheets, which is isolated by a layer of h-BN. A silver nano-ribbon with sharp rectangular edges can serve as a guide for a spatially confined plasmonic mode. There are two edges involving in the presence of transverse electric field components that contribute to the interaction. Our results show a high amount of light confinement and surface plasmon polaritons. The proposed modulator has a 11.8 dB/µm modulation depth with 1.7 dB/µm loss at 1550 nm and a 19.9 dB/µm modulation depth with 2.9 dB/µm loss at 1300 nm.