▎ 摘　　要

The modulation of the transmitted (reflected) radiation due to change of interband transitions under variation of carriers concentration by the gate voltage is studied theoretically. The calculations were performed for strongly doped graphene on high-kappa (Al2O3, HfO2, AlN, and ZrO2) or SiO2 substrates under normal propagation of radiation. We have obtained the modulation depth above 10% depending on wavelength, gate voltage (i.e., carriers concentration), and parameters of substrate. The graphene-dielectric substrate-doped Si (as gate) structures can be used as an effective electrooptical modulator of near-IR and mid-IR radiation for the cases of high-kappa and SiO2 substrates, respectively. (C) 2011 American Institute of Physics. [doi:10.1063/1.3653837]