The modal properties and modulation characteristics of the fundamental gap mode supported by nanowire based symmetrical IMI graphene hybrid plasmonic waveguide are investigated employing the finite element method. The proposed modulator even with its remarkably small footprint offers both high extinction ratio (as high as 40 dB) and large modulation bandwidth (as large as 237 GHz) simultaneously with only 2.4 μm long active region at the telecommunication wavelength. The optical capacitance effect along with IMI like mode coupling are reported here for this improved modulation performance. Furthermore, a deep subwavelength mode size (λ2/400) with low energy consumption per bit (as small as 0.9 fJ/bit) suggests its highly dense integration in photonic integrated circuits. Also, the performance variation of this waveguide is explored with respect to the alteration of operating wavelength and cross-sectional geometry.
