Abstact-Tunable terahertz reflection of graphene via ionic liquid gating

Yang Wu, Xuepeng Qiu, Hongwei Liu, Jingbo Liu, Yuanfu Chen, Lin Ke, Hyunsoo Yang

(Submitted on 1 Feb 2017)

https://arxiv.org/abs/1702.00114

We report a highly efficient tunable THz reflector in graphene. By applying a small gate voltage (up to 3 V), the reflectance of graphene is modulated from a minimum of 0.79% to a maximum of 33.4% using graphene/ionic liquid structures at room temperature, and the reflection tuning is uniform within a wide spectral range (0.1 - 1.5 THz). Our observation is explained by the Drude model, which describes the THz wave-induced intraband transition in graphene. This tunable reflectance of graphene may contribute to broadband THz mirrors, deformable THz mirrors, variable THz beam splitters and other optical components.