Terahertz multifunctional elements based on all-dielectric metamaterials

A multifunctional terahertz element (MTE) was constructed with a silicon substrate etched with periodically distributed rectangular holes, integrating the functions of a quarter-wave plate, half-wave plate, and reflector. Results show that the quarter-wave plate has a transmittance of over 90 % within a bandwidth exceeding 1 THz, the half-wave plate achieves nearly 100 % polarization conversion efficiency at 5 THz, and the reflector maintains 100 % reflectivity within the frequency range of 13 THz to 21 THz. It suitable for photonic chip integration to achieve polarization control and filtering, with broad applications in sensing, detection, and photonic computing.