Mathematical Operations of Transmissive Near Fields Controlled by Metasurface with Phase and Amplitude Modulations

Metasurfaces show great potential due to their powerful ability to manipulate electromagnetic waves as desired, which has been widely investigated in the microwave, terahertz, infrared, and visible regimes. Here, it is proposed to control near-field distributions through use of a metasurface with both amplitude and phase modulations. A C-shaped particle is designed to provide stable and continuous amplitude and phase profiles independently of transmitted waves by varying its opening and orientation angles. Benefiting from both amplitude and phase modulations on the metasurface, differentiation and integration on electric-field distributions can be achieved by changing the arrangements of complex coefficients on the metasurface. Besides, the differential operation can be utilized to show the edges of predesigned electric-field distributions. It is believed that the proposed method will accelerate the pace of metasurfaces towards many applications by engineering and operating the near-field distributions.