Tunable Fano resonator using multilayer graphene in the near-infrared region

Fano resonance (FR) holds promising applications for high performance optoelectronic devices due to its strong enhancement of light-matter interactions. In this work, we experimentally demonstrate a tunable FR in a photonic crystal nanoresonator (PCR), including the effects of structural parameters and graphene nanosheets with different layer numbers. The results show that the intensity and position of Fano peaks can be tuned via altering the lattice constant and the hole radius of PCR due to the variation of the effective refractive index. More importantly, we experimentally study the interaction between sharp FR with multilayer graphene. The results indicate that the FR transmission spectrum can be efficiently adjusted with the layer number of graphene, and the largest change in transmission (∼44%) is achieved with three-layer graphene because of high conductivity. These consequences may lead to efficient and tunable electro-optical modulators, biosensors, and optical switches in the near-infrared region.