High Refractive Index Metasurface for Terahertz Flat Optics

Abstract

High refractive index metasurfaces can provide an accessible platform for terahertz flat optics with a variety of continuous-wave (CW) sources. We present a metasurface collimator that enhances the directivity of a terahertz CW source as a first application based on our original reflectionless metasurface with a high refractive index. Measurements confirm the directivity enhancement of 2.3 times at the far field with a resonant-tunneling diode oscillating at 0.312 THz. The proposed metasurface collimator can be incorporated in various beam shaping components and contribute to the development of terahertz applications such as wireless communication in the advanced generation 6G and imaging.