Design of a low power silicon-plasmonic hybrid electro-optic modulator relied on ITO

In this paper, a low power silicon-plasmonic hybrid electro-optic modulator relied on Indium Tin Oxide (ITO) has been proposed and designed. The proposed modulator is based on a three-coupled waveguide; two silicon waveguides and one hybrid plasmonic waveguide. A hybrid plasmonic horizontal waveguide with two ITO layers separates two silicon waveguides. Balancing between extinction ratio (ER) and insertion loss (IL) requires a trade-off when designing an optical modulator. The structure is proposed as a modulator that alleviates this trade-off. The structure has two ITO layers with an epsilon near zero (ENZ) effect for increasing light-matter interaction, maximizing optical mode's attenuating and disrupting the optical coupling. In the designed structure, amplitude modulation with high ER and, at the same time, low IL are obtained. The designed device is broadband with low power consumption. The ER, IL, and power consumption values were 16.05 dB, 0.3 dB, and 16.2 fJ. The finite-difference time-domain (FDTD) method is used to investigate the properties of the proposed modulator. •Silicon-based waveguides with Indium Tin Oxide as a plasmonic material could use to design high-performance modulators.•The modulator with coupled waveguides is designed using the ITO-dielectric-Si-dielectric-ITO horizontal stack waveguide.•Using the two ITO layers embedded in the plasmonic waveguide increases the light-matter interaction.