Bandwidth-tunable Terahertz Metamaterial Half-Wave Plate Component

We propose a l"eaf-type" hybrid metamaterial to realize bandwidth-tunable half-wave plate based on vanadium dioxide (VO2) phase transition. The hybrid metamaterial is regarded as a hollow "leaf-type" metallic structure and act as a dual-band half-wave plate when VO2 film is in the insulating phase. Within 1.01- 1.17 THz and 1.47-1.95 THz, it can accomplish y- to x-polarization conversion with a polarization conver-sion rate over 0.9 and an average relative bandwidth of 26%. The metamaterial becomes a solid core l"eaf-type" metallic structure when VO2 is in the metallic phase. Within 1.13-2.80 THz, it can act as a broadband half-wave plate with a relative bandwidth of 85%. The working principle of the bandwidth-tunable half-wave plate is explained by the instantaneous surface current distribution and electric field theory in detail. The pro-posed l"eaf-type" hybrid metamaterial half-wave plate has potential application prospects in THz imaging, sensing and polarization detection.