Feasibility of Coherent Perfect Absorption Based on Spoof Surface Plasmon Polaritons

The coherent perfect absorption (CPA) technology has gained extensive attention in recent years. This study explores strips array configurations based on Spoof Surface Plasmon Polaritons (SSPP) to demonstrate their feasibility in achieving electromagnetic CPA by simulations. Leveraging the dispersion characteristics of metal strips of specific dimensions, electromagnetic absorption can be achieved at the corresponding frequency points. The SSPP absorptive structure is strategically positioned within the standing wave field formed by two counter-propagating coherent waves. Manipulating the phase of the control wave facilitates dynamic adjustment of the absorber’s location within the standing wave field, thereby selectively enhancing or attenuating the coherent absorption effect. Particularly, the control wave’s phases of 0° and 180° correspond to the two extremes for the coherent absorption. Furthermore, the frequency of the absorption peak can be manipulated by varying the size of the metal strips. Based on the above findings, this paper further presents a dual-polarized SSPP-based coherent absorber and a multi-frequency SSPP-based coherent absorber.