Tunable Autler-Townes splitting using graphene-based electro-optic effect

We propose a tunable Autler-Townes splitting (ATS) window using the electro-optic effect. The proposed structure includes two cascaded silicon ring resonators side coupled to a straight waveguide. The electro-optic effect is created by a nano-layer graphene located on half of lower silicon ring resonator. Here for the first time, ATS window frequency location is adjusted by utilizing a graphene nano-sheet, so that its wavelength shift is more than 0.24 nm via changing the graphene chemical potential level from 0.445 eV to 0.667 eV. Moreover, we simulate and show the phase changes of the transmission curves around ATS frequency window and their corresponding group delays. Furthermore, switching from slow (fast) to fast (slow) light is another interesting phenomenon of the proposed structure. (C) 2018 Elsevier B.V. All rights reserved.