High-efficiency reflective terahertz cross-polarization converter with broadband and wide-angle response

In this paper, a broadband terahertz metasurface dedicated to cross-polarization conversion was designed, fabricated, and assessed. The metasurface, comprising two nested double-split rings, features an inherent insensitivity to the angle of incidence. Simulations reveal that the converter achieves a > 99% polarization conversion efficiency across the 90-140 GHz range. Moreover, it maintains a > 90% polarization conversion ratio (PCR), even at a 50 degrees incidence angle. The sample, featuring 50 x 70 arrays, was fabricated, and the relevant experimental results align closely with the simulated outcomes. The metasurface characteristics can markedly enhance the performance of cross-polarization converters operating in the terahertz range. (c) 2024 Optica Publishing Group