Design of terahertz beam splitter based on I-shaped double open ring structure

Abstract

This paper presents a terahertz beam splitter based on an "I" type double open ring structure. Its structure unit is a typical metal-medium-metal structure; the top metal pattern comprises an "I" type double open ring, and the bottom layer is a continuous metal plate. The phase gradient metasurface of 8 × 8 is formed by changing the opening size and radius of the I-shaped double-open ring. When a y-polarized wave is an incident vertically along the -z-axis and the +z axis, respectively, the y-polarized waves will be divided into four beams with different energy distributions along the x and y-axis, and two different beam splitting ratios can be obtained from the two incident modes. In 0.7 THz, when the y polarized waves are incident vertically along the -z-axis and +z axis, the beam splitting ratio is 0.8 and 2.1, respectively, and the beam splitting ratio is tuned. This terahertz beam splitter has the advantages of small size and low cost and can be used in terahertz communication, terahertz imaging, terahertz stealth, and other fields.