Abstract-Broadband phase shift engineering for terahertz waves based on dielectric metasurface

Qianyi Mu, Hengzhi Lin, Fei Fan, Jierong Cheng, Xianghui Wang, Sheng Jiang,




https://www.sciencedirect.com/science/article/abs/pii/S0030401818309143
Broadband terahertz (THz) phase shift engineering and zero-dispersion waveplates based on dielectric metasurface have been investigated, of which structure is a periodical rectangular scattering units on silicon substrates. By designing proper geometric parameters of metasurface structure, the value, dispersion and bandwidth of the phase shift curves can be effectively manipulated. Based on this, the broadband half waveplate (HWP) and quarter waveplate (QWP) have been designed and fabricated. The experimental results show that the HWP can work in the broad range of 0.7–1.35 THz with the polarization conversion ratio (PCR) of close to 100% and the transmission of over 70%. And the QWP can operate in the range of 0.7$\sim$0.85THz with the PCR of over 90% and the transmission of over 70%. The method of phase shift engineering based on dielectric metasurfaces and these broadband zero-dispersion waveplates have great potential in promoting the performance of THz application systems.