High-performance electro-optical switch using an anisotropic graphene-based one-dimensional photonic crystal

A novel electro-optical switch is proposed and investigated using the transfer matrix method (TMM) and three-dimensional finite-difference time-domain (3D FDTD) analysis at the near-infrared range. The structure is made of a defect at the middle of a one-dimensional photonic crystal. The defect consists of two anisotropic graphene (AG) sheets separated by a dielectric layer. As a result, a sharp transmission peak with a high quality factor of 5000 appears at the wavelength of 1552.4 nm where light is trapped by the defect. When an external voltage is applied across the AG sheets, their chemical potentials shift in such a way that the trapped photons are absorbed and the switch changes to ON state. According to the presented results, a high extinction ratio of 14.26 dB with a very low insertion loss of 0.18 dB are obtained. The required switching voltage and energy consumption are as low as 4.68 V and 226 fJ/bit, respectively. The 3 dB bandwidth is also calculated to be as high as 17.5 GHz, which makes our proposed switch promising for high speed optical systems.