A novel terahertz beam splitter using ultrathin flexible transmission-type coding metasurface

摘要

A new flexible and simple transmission-type coding metasurface was proposed and characterized, which can generate different transmitted beam patterns by coding sequences of "0" and "1" digital elements. The two digital elements with almost identical transmission amplitude are composed of three metallic layers and three dielectric layers, and their transmission phase difference is approximately 180 degrees at 0.95 THz. The characterizations and working mechanisms of the coding metasurface were investigated through theoretical analysis and electromagnetic (EM) simulation. The simulation and theoretical analysis results show that the normally incident waves will be realized a single beam, two main beams and four main beams, respectively using different transmission-type coding sequences. And the amplitude modulation of transmission beam was realized by an optical pump beam. This work reveals a new and simple route for designing novel terahertz beam splitter and offers widespread applications.