Fig. 1. Herringbone metasurfaceunit structure: (a) Three-dimensional of unit structure; (b) two-simensional of unit structure.人字形超表面单元结构　(a)单元结构三维立体图; (b)单元结构二维平面图

Fig. 2. The basic unit structure and characteristic curves of four kinds of herringbone metasurface: (a) Unit A (L = 48 μm); (b) unit B (L = 40 μm); (c) unit C (L = 34 μm); (d) unit D (L = 20 μm); (e) reflectivity of four unitsfrom 0.4 THz to 1.0 THz; (f) reflection phase of four units from 0.4 THz to 1.0 THz. 4种人字形超表面基本单元结构及其特性曲线　(a) A单元(L = 48 μm); (b) B单元(L = 40 μm); (c) C单元(L = 34 μm); (d) D单元(L = 20 μm); (e) 4种单元在0.4 THz到1.0 THz下的反射率; (f) 4种单元在0.4 THz到1.0 THz下的反射相位

Fig. 3. The terahertz frequency coding metasurface: (a) 1-bit periodic terahertz frequency coding metasurface arranged along x direction with “0-0, 0-1, 0-0, 0-1” sequence; (b) chessboard 1-bit periodic terahertz frequency coding metasurface; (c) 2-bit periodic terahertz frequency coding metasurface arranged along x direction with “00-00, 00-01, 00-10, 00-11” sequence; (d) 2-bit random terahertz frequency coding metasurface; (e) 2-bit non-periodic terahertz frequency coding metasurface. 太赫兹频率编码器　(a)以“0-0, 0-1, 0-0, 0-1”序列沿x方向排列1-bit周期太赫兹频率编码器; (b)棋盘式1-bit周期太赫兹频率编码器; (c)以“00-00, 00-01, 00-10, 00-11”序列沿x方向排列2-bit周期太赫兹频率编码器; (d) 2-bit随机太赫兹频率编码器; (e) 2-bit非周期太赫兹频率编码器

Fig. 4. 1-bit terahertz frequency coding metasurface arranged periodically along x direction with sequence “0-0,0-1, 0-0, 0-1”: Three-dimensional far-field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. 序列“0-0, 0-1, 0-0, 0-1”沿x方向上周期排布的1-bit太赫兹频率编码器　(a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时的三维远场图

Fig. 5. 1-bit terahertz frequency coding metasurface arranged periodically along x direction with sequence“0-0, 0-1, 0-0, 0-1”: Two-dimensional electric field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. 序列“0-0, 0-1, 0-0, 0-1”沿x方向上周期排布的1-bit太赫兹频率编码器　(a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时的二维电场图

Fig. 6. Chessboard 1-bit terahertz frequency coding metasurface: Three-dimensional far-field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. 棋盘式1-bit太赫兹频率编码器　(a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时的三维远场图

Fig. 7. Chessboard 1-bit terahertz frequency coding metasurface: Two-dimensional electric field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. 棋盘式1-bit太赫兹频率编码器　(a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时的二维电场图

Fig. 8. 2-bit periodic terahertz frequency coding metasurfacearranged along x direction with “00-00, 00-01, 00-10, 00-11” sequence: Three-dimensionalfar-field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. “00-00, 00-01, 00-10, 00-11”周期排布的2-bit太赫兹频率编码器　(a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时的三维远场图

Fig. 9. 2-bit periodic terahertz frequency coding metasurface arranged along x direction with “00-00, 00-01, 00-10, 00-11” sequence: Two-dimensionalelectric field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. “00-00, 00-01, 00-10, 00-11”周期排布的2-bit太赫兹频率编码器　(a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时的二维电场图

Fig. 10. 2-bit random terahertz frequency coding metasurface: Three-dimensional far-field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. 2-bit太赫兹随机频率编码器　(a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时的三维远场图

Fig. 11. 2-bit random terahertz frequency coding metasurface:two-dimensional electric field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. 2-bit太赫兹随机频率编码器　(a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时二维电场图

Fig. 12. Radar cross section distribution of 2-bit terahertz random frequency coding metasurface and metal plate at 1.0 THz.2-bit太赫兹随机频率编码器和金属板在1.0 THz处的雷达散射截面分布

Fig. 13. Fig. 10. 2-bit non-periodic terahertz frequency coding metasurface: Three-dimensional far-field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. 2-bit非周期排布太赫兹频率编码器 (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时的三维远场图

Fig. 14. Fig. 10. 2-bit non-periodic terahertz frequency coding metasurface: Two-dimensional electric field pattern of (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz. 2-bit非周期排布太赫兹频率编码器 (a) f = 0.4 THz, (b) f = 0.75 THz, (c) f = 0.95 THz, (d) f = 1.0 THz时的二维电场图

Table 1. 1-bit frequency terahertz coding metasurface unit.