Active Polarization Modulation of Terahertz Radiation Using Metamaterial/Graphene-Based Optoelectronic Devices

We investigate the modulation performance of a metamaterial/graphene optoelectronic device in the THz range. Operating characteristics such as amplitude, phase and polarization modulations of broadband THz radiation are reported. The accomplishments of modulation depth include >75% in spectral amplitude, $\gt 15^{\circ}$ in spectral phase, $\gt 0.2$ active modulation of ellipticity ratio, and active rotational angle changes of 20°. These achievements are the key elements towards efficient manipulations of THz radiation for applications such as next-generation wireless communications, spectroscopy, and imaging.