The Polarization-Controllable Graphene-Assisted Ring Modulator

The polarization-controllable graphene-assisted ring modulator is proposed. By adjusting the applied voltage of graphene films in horizontal and perpendicular directions, TE and TM modulation can be realized and switched within one ring modulator. The proposed ring modulator can also function as either an electro-refraction or electro-absorption modulator by adjusting the real and imaginary parts of effective modal index of graphene. In this article, both electro-refraction and electro-absorption ring modulators featuring TE/TM polarization independence are configured and investigated, results show that regardless of being tuned as the electrorefraction or electro-absorption modulation, the proposed polarization-controllable graphene ring modulator features high extinction ratio exceeding 10 dB, large 3-dB bandwidth of over 87.5 GHz, and low consumption of 5.6 fJ/bit.