Design and simulation of compact subwavelength electro-optic switch based on graphene surface plasmon polaritons

In this study, a small electro-optic switch is designed and simulated by designing a plasmonic waveguide with high confinement. By using a silicon ridge near graphene and adjusting its chemical potential, a plasmonic channel is provided that controls the optical signals transmission depending on the graphene chemical potential. By applying chemical potentials of 0.1 eV and 0.5 eV, the channel loss for frequencies ranging from 25 to 45 THz changes from 78.03 to 0.23 dB/µm. The structure size is 0.057 µm2, which is smaller than similar structures. The small size of the structure is one of the fundamental requirements of optical integrated circuit designing. This feature, along with a coupling length of 218.2 µm and a figure of merit of 1246, indicates that surface plasmons are well confined and guided in the designed channel. With regard to the obtained results, the designed plasmonic switch can be proposed for various analog and digital applications.