Linear polarization characteristics of broadband half-wave plate based on monolayer all-dielectric metamaterials

In this paper, a modular half-wave plate (HWP) set based on monolayer all-dielectric metamaterials is designed, which can realize broadband performances of HWP in transmission mode. By rotating and superimposing each layer of HWPs with different specific angles, the polarization directions of linearly polarized incident wave can be rotated by 20 effectively in the broadband range with specific angle combinations. The broadband performances of the HWP set can be achieved at the frequency band of 0.80-1.13 THz, and the PCR was over 95%. The polarization conversion rate (X-polarization to Y-polarization) was maintained at about 40% in the 0.75-0.95 THz. By analyzing and calculating the composite pulse control, the precise rotation angle of each layer's HWP can be obtained. This combination method can be effectively extended and widely applied to many kinds of transmission type metamaterial HWPs.