▎ 摘　　要

Wavelength-tunable plasmon-induced transparency (PIT) in coupled graphene gratings was theoretically investigated in mid-infrared region. Both direct and phase-coupled PITs were considered in the proposed structure. In both schemes, a proper wavelength detuning between two graphene gratings was required for PIT observations. The effect of graphene quality on the PIT was also investigated. Graphene quality of mu = 50,000 cm(2)/Vs was sufficient for achieving a distinct PIT peak while a weak PIT was observed for mu = 10,000 cm(2)/Vs. PIT peak amplitude modulation and tunability of operating wavelength were demonstrated by adjusting the Fermi level of graphene. Compared with previously studied graphene-based PITs, the proposed PIT based on the coupled graphene gratings is much easier to design and fabricate.