Two-dimensional graphene-plasmonic crystals for all-optical switch applications

The present study experimentally and theoretically demonstrated an all-optical switch based on a two-dimensional plasmonic crystal structure which was covered by a graphene layer. The optical modes in the photonic band gap of the crystal can be tuned due to the surface plasmon resonance of plasmonic crystal and nonlinear Kerr effect of graphene. Therefore, in the present study, the plasmon resonance wavelength was shifted about 10 and 2.1 nm for the transverse electric and the magnetic polarization in 58° incident angle, respectively. To get switching manner, by applying the 1550 nm infrared laser as a pump the electric field was increased due to large Kerr nonlinearity of graphene, $$n_{2} \approx$$ 10−7cm2/W. As a result, refractive index was changed and thus the resonance wavelength of surface plasmon was shifted. In order to confirm the experimental results, Kerr nonlinear effect of graphene, and optical electric field distribution at resonance wavelength have been simulated. Based on the results, this switch had three main advantages such as small size, high tunablitiy, and easier fabrication compared to the other methods, which use defect photonic crystal structures.