▎ 摘　　要

We consider a planar layered structure including a graphene sheet with an unexpected transmission of the beam in total internal reflection angles. In this paper, we investigate this particular response through the excitation of leaky type surface plasmons of graphene and the coupling of surface plasmons to far-field radiations. Dependence of the transmission on the chemical potential of graphene is investigated and maximized by optimization techniques. Thus, for a fixed frequency and angle of incident beam, the transmission coefficient can be set between 0 and a maximum value (up to more than 0.9) by tuning the chemical potential of graphene via the applied voltage. This effect can be used in design of tunable optoelectronic frequency/angle switches.