We present three rotation symmetric planar metamaterials and consist of 3, 4 and 6 split resonant rings (SRRs) respectively, proved that they are polarization-insensitive. The modulation characters constructed by the three planar metamaterials are also studied and compared to demonstrate that the structure with more even rotation symmetry is much more beneficial to be polarization-independence. Furthermore, the influencing rules of the electrodes on the polarization character of metamaterials are obtained. The polarization character can be converted by tailoring the electrodes which provides a guide to construct and design novel terahertz polarimetirc devices for potential applications.
We demonstrate that the transmission properties of terahertz metamaterials based on split-ring resonators (SRR) is significantly dependent upon the incident wave polarization. Structures with different rotation symmetry are patterned on intrinsic gallium arsenide (GaAs), and examined in our work with finite element method. The EM responses of proposed structures under different polarization incidence THz wave are simulated. The simulation results demonstrate that the polarization-sensitive characteristic is determined by the rotation symmetry of the SRR - metamaterials units. Our work can be a guide for the design of novel metamaterials modulator and other polarimetric THz devices.