Active terahertz modulations based on graphene-silicon hybrid structures

With simultaneous optical and electrical excitations, we experimentally demonstrate an active modulation of transmitted terahertz waves through a graphene-silicon hybrid structure. A large transmission modulation of 83% was observed. Meanwhile, a “diode” behavior was found in such a structure, where terahertz waves transmits when biased with a positive voltage while attenuates under a low negative voltage.