Numerical Analyze of a Broadband Optical Modulator Based on Bilayer Graphene and h-BN in the Wavelength range of 1300 to 1800 nm with High Extinction Ratio

In this paper, a broadband optical modulator containing two bilayers of graphene and h-BN is designed and analyzed. Graphene monolayers with sub-wavelength thickness and tunable absorption rates have become a key element in optical device design. The h-BN dielectric layer has been used to maintain the properties of graphene monolayers in structures containing two or more graphene layers. In this paper, the proposed optical modulator structure consists of two bilayers of graphene and h-BN layers which apply voltage to the graphene layers which modifies the chemical potential of graphene and by controlling the amount of graphene absorption, modulation of the light output is provided. The proposed structure for the modulator is studied by calculating the modulatorchr('39')s performance characteristics through the FDTD method. The proposed modulator has a proper performance in the wavelength range of 1800-1300 nm and it exhibits the modulation depth 0.12 dB/µm and the extinction ratio 12 dB with the insertion loss 0.16 dB/µm at wavelength of 1550 nm.