Fig. 1. Schematic diagram of the proposed structure.

Fig. 2. Transmission and reflection spectra of the whole structure and the absorption spectra of the graphene layer.

Fig. 3. (a) Absorption spectrum of graphene with different α values; (b) variation in the absorption at 1550 nm as a function of α.

Fig. 4. Angle responses of graphene absorption.

Fig. 5. (a) and (b) Real and imaginary parts of the complex permittivity of graphene for different chemical potential μ; (c) the absorption of graphene as a function of the chemical potential μ.

Fig. 6. (a) Absorption of graphene with different E_y values; (b) modulation depth for different E_y values; (c) and (d) modulation depth for E_y = ±0.02 V/nm.