Highly efficient graphene terahertz modulator with tunable electromagnetically induced transparency-like transmission

Graphene-based optical modulators have been extensively studied owing to the high mobility and tunable permittivity of graphene. However, weak graphene-light interactions make it difficult to achieve a high modulation depth with low energy consumption. Here, we propose a high-performance graphene-based optical modulator consisting of a photonic crystal structure and a waveguide with graphene that exhibits an electromagnetically-induced-transparency-like (EIT-like) transmission spectrum at terahertz frequency. The high quality-factor guiding mode to generate the EIT-like transmission enhances light-graphene interaction, and the designed modulator achieves a high modulation depth of 98% with a significantly small Fermi level shift of 0.05 eV. The proposed scheme can be utilized in active optical devices that require low power consumption.

Automated summary

Graphene-based optical modulators have been widely studied, but weak graphene-light interactions limit the achievement of high modulation depth with low energy consumption. In this study, a high-performance graphene-based optical modulator, consisting of a photonic crystal structure and a waveguide, is proposed. It exhibits an electromagnetically-induced-transparency-like transmission spectrum at terahertz frequency, enhancing light-graphene interaction. The designed modulator achieves a high modulation depth of 98% with a small Fermi level shift of 0.05 eV, making it suitable for low power consumption in active optical devices.