Research And Design Of Metamaterial Coherent Perfect Absorbe

Metamaterial,an artificial material,has special optical properties that natural materials do not have.Such special optical properties can modulate the amplitude,phase and polarization of optical field in sub-wavelength scale.As a typical representative of amplitude manipulation,electromagnetic absorption plays an important role in many fields such as stealth technology,solar cells,and signal shielding.Therefore,the metamaterial perfect absorber has become one of the focuses research in nano-photonics.The metamaterial coherent perfect absorber,which are from the combining metamaterial absorber with coherent technology,has attracted much attention due to its perfect absorption and flexible tunability.In this paper,the metamaterial coherent perfect absorber and its working mechanism are studied in detail.The vanadium dioxide metamaterial coherent perfect absorber,lithium niobate metamaterial coherent perfect absorber are designed.The finite element method is used to calculate and analyze the designed metamaterial coherent perfect absorbers.The main contents of the paper are as follow:1.Research background,development and research status of metamaterial,metamaterial absorber and metamaterial coherent perfect absorber are briefly introduced.2.Theory of the metamaterial coherent perfect absorber and all-optical modulation are introduced in detail by using single-layer graphene structure.The similarities and differences between metamaterial coherent perfect absorber and traditional metamaterial absorber are discussed.Finally,the numerical simulation method and simulation modeling process used in the research work of this article are introduced briefly.3.Basing on the phase transition character of VO₂,a multifunctional tunable metamaterial coherent perfect absorber is designed.The working mechanism of its perfect absorption,switching conditions for broad-band and narrow-band modes and influences of geometric parameters are analyzed in detail.Finally,the all-optical modulation and polarization independent characteristics of the metamaterial coherent perfect absorber are analyzed.4.Basing on the electro-optical effect of Li Nb O₃,a near infrared tunable metamaterial absorber is designed.Its absorption mechanism and tunability characteristic are analyzed.Then,a Li Nb O₃ metamaterial coherent perfect absorber is designed by combining the Li Nb O₃ metamaterial absorber with coherent technology.The working mechanism of its perfect absorption,relation between resonant frequency and the applied voltage,influences of polarization angle and character of all-optical modulation are analyzed in detail.The research work in this paper provides a theoretical base and guiding idea for the design of multifunctional tunable metamaterial coherent perfect absorber.In addition,the designed multifunctional tunable metamaterial coherent perfect absorber has potential applications in stealth technology,communication,optical devices and other fields.