Dielectric-resonator metasurfaces for broadband terahertz quarter- and half-wave mirrors.
Wendy SL Lee, Rajour T Ako, Mei Xian Low, Madhu Bhaskaran, Sharath Sriram, Christophe Fumeaux, Withawat Withayachumnankul
Optics Express | Published : 2018
Polarization conversion of terahertz waves is important for applications in imaging and communications. Conventional wave plates used for polarization conversion are inherently bulky and operate at discrete wavelengths. As a substitute, we employ reflective metasurfaces composed of subwavelength resonators to obtain similar functionality but with enhanced performance. More specifically, we demonstrate low-order dielectric resonators in place of commonly used planar metallic resonators to achieve high radiation efficiencies. As a demonstration of the concept, we present firstly, a quarter-wave mirror that converts 45° incident linearly polarized waves into circularly polarized waves. Next, we..View full abstract