Coherent perfect absorption and transparency in a nanostructured graphene film

We show numerically that both coherent perfect absorption and transparency can be realized in a monolayer graphene. The graphene film, doped and patterned with a periodical array of holes, can support plasmonic resonances in the Mid-infrared range. Under the illumination of two counter-propagating coherent optical beams, resonant optical absorption may be tuned continuously from 99.93% to less than 0.01% by controlling their relative phase which gives a modulation contrast of 40 dB (about 30 dB for transmission). The phenomenon provides a versatile platform for manipulating the interaction between light and graphene and may serve applications in optical modulators, transducers, sensors and coherent detectors.