Coherent Perfect Absorption Based On Metamaterials

Metamaterials can achieve a large number of unique electromagnetic properties,which cannot be found in natural materials.As a cutting-edge multidisciplinary field,metamaterials can open a new opportunity to realize novel optoelectric devices and data processing.However,processing of photonic information usually relies on electronics and hampers its innovation.In this proposal,optical controlled metamaterials are studied theoretically.The selective absorption can be coherently modulated by use of the standing wave in order to achieve new all-optical functional devices.The main works are as follows:Firstly,by use of the transmission and scatting matrix,the mechanism of the interaction between the standing wave and the metamaterials is studied.The excited electromagnetic modes of metamaterials in the standing wave are discussed and the condition is summarized to realize the perfect coherent absorption.The recognition of the overlapped electric and magnetic resonances is explored based on the coherent technique.Secondly,the bilayered asymmetric metamaterials are designed.When the single beam illuminates it normally,three absorption peaks appear and each one reaches 50%.The interaction between the standing wave and the metamaterial is further discussed,and the results show that the electronic and magnetic mode can be selectively excited in terms of the relative phase difference between two incident beams.The absorption of three peaks can be modulated between 0 and 1 and thus the coherent perfect absorption can be realized.When the phase difference between two beams changes,the electromagnetic modes can be selectively switched on/off.Thirdly,3D metamaterials are constructed based on the symmetric and asymmetric split rings.The electromagnetic resonance in the case of single beam illumination is studied.Moreover,the interaction between the 3D structural metamaterials and the standing wave are discussed to recognize the electromagnetic modes,and the evolution of the response is investigated in detail.The coherent absorption phenomenon of the 3D structural metamaterials is discussed.