Coherent perfect absorption from asymmetry transmissive Helmholtz resonator metamaterials

We propose an asymmetry transmissive (AT) Helmholtz resonator metamaterial to interact with dual incidences of different polarizations from opposite directions to achieve coherent perfect absorption at a terahertz regime. More specifically, the proposed design will solely allow the x-polarized incidence tunnel into the Helmholtz resonator cavity array with roughly half the energy reflected. Meanwhile, the transmitted fields will be converted into the y-polarized counterparts so as to go out through the metamaterial and finally coherent canceled with the partially reflected fields of the other incidence. Our design, introducing the Helmholtz resonator array in the electromagnetics with an extension of the principle of polarization conversion under the coherent perfect absorption, should pave the way for the quest of building up more advanced wave trapping meta-devices for various applications in different disciplines.