Tunable control of electromagnetically induced transparency analogue in a compact graphene-based waveguide.

An easily-integrated compact graphene-based waveguide structure is proposed to achieve an analogue of electromagnetically induced transparency (EIT) effect at terahertz frequencies. The structure is composed of a graphene waveguide and two identical-shape graphene ribbons located parallel on the same side of the waveguide at different distances, in which the closer and the farther ribbons behave as the bright and the dark resonators, respectively. The EIT-like effect is caused by the destructive interference of the two resonators. By shifting the Fermi energy levels of ribbons, the transparency window can be dynamically tuned. The structure may offer another way for tunable integrated optical devices.