Large‐Area 3D‐Printed Chiral Metasurface Composed of Metal Helices

Abstract An original design for chiral metasurfaces formation is proposed. The hybrid fabrication approach is based on the 3D printing of polymer substrates with a shape‐generating “helical” relief, molding, and subsequent shadow metal deposition. The formed double‐layer grating of multiturn metal helices rotates the polarization plane of sub‐terahertz and microwave radiation through an angle in excess of 40°. Both experimentally and in numerical simulations, it is demonstrated that re‐reflection phenomena occur in the “metal helix–polymer substrate” hybrid structure. Those phenomena permit control of polarization‐plane rotation, ellipticity, and asymmetric transmission. Multiplication of printed structures with 3D helices achieved by using the molding technique enables the formation of large‐area chiral metasurfaces. The advantages of the proposed metasurface include easy fabrication of the system, the possibility of its scalability to other frequency ranges, and the possibility of using systems based on such metasurfaces in highly efficient polarization transformers.