Multidimensional manipulation of broadband absorption with dual-controlled terahertz metamaterial absorbers

In this paper, we develop a dual-controlled graphene plasmon-based broadband metamaterial absorber (BMMA) integrating the photosensitive silicon. The designed device can implement active frequency, intensity, and bandwidth modulations of broadband absorption by electrically doping graphene and optically pumping silicon individually or simultaneously, featuring terahertz devices with multidimensional manipulation. To interpret the modulation mechanism of the broadband absorption, an equivalent circuit model based on the transmission line theory is constructed, and theorical results agree well with the simulated ones. In addition, the absorption characteristics depending on polarization angles, incident angles, and structural parameters are also systematically investigated. Therefore, the proposed broadband metamaterial absorber with multidimensional tunability endowed by dual-controlled mode could have potential applications on the design of active and multifunctional terahertz metadevices, such attenuators, modulators, selectors, and detectors.