Multipolar-interference-assisted terahertz waveplates via all-dielectric metamaterials

Polarization control via metamaterials boosts the design of polarimetric devices in the realm of terahertz technology for sensitive detection, bio-imaging, and wireless communication. Here, we propose all-dielectric metamaterials composed of silicon brick arrays that operate as terahertz quarter- and half-waveplates with close to unity transmission. Spherical multipole decomposition calculation indicates that the silicon brick can support multiple Mie-type resonances, such as electric dipole, electric quadrupole, magnetic dipole, and magnetic quadrupole modes. By tailoring the multipolar interference among these resonances, near unity transmission can be obtained with over π phase delay. We experimentally realize dielectric terahertz metamaterials that function as a quarter-wave plate at 0.79 THz and a half-wave plate at 0.91 THz with insertion losses of 0.54 and 1.25 dB, respectively. Such anisotropic dielectric metamaterials promise an exotic approach to engineer the interference among multipolar resonances and reveal the feasibility to realize functional, efficient, and compact terahertz meta-devices.Polarization control via metamaterials boosts the design of polarimetric devices in the realm of terahertz technology for sensitive detection, bio-imaging, and wireless communication. Here, we propose all-dielectric metamaterials composed of silicon brick arrays that operate as terahertz quarter- and half-waveplates with close to unity transmission. Spherical multipole decomposition calculation indicates that the silicon brick can support multiple Mie-type resonances, such as electric dipole, electric quadrupole, magnetic dipole, and magnetic quadrupole modes. By tailoring the multipolar interference among these resonances, near unity transmission can be obtained with over π phase delay. We experimentally realize dielectric terahertz metamaterials that function as a quarter-wave plate at 0.79 THz and a half-wave plate at 0.91 THz with insertion losses of 0.54 and 1.25 dB, respectively. Such anisotropic dielectric metamaterials promise an exotic approach to engineer the interference among multipolar resona...