| In this paper, metal-dielectric-metal (MDM) sandwich structure metamaterials have been studied with negative refractive index, negative permeability and other characteristics. These metamaterials can achieve extraordinary optical transmission, negative refraction, resistance bands, broad passband and so on by optimizing the design of structure. This paper contains three parts:the first part is the preparation of MDM metamaterial samples and using Fourier transform infrared spectroscopy to measure the transmittance of the metamaterial sample. The second part is the influence of the design of structure on the electromagnetic properties of metamaterials and its physical mechanis. The third part is the realization of functional devices metamaterials include stop-band filter, pass-band filter, as well as sample preparation of the passband filter metamaterials. Meanwhile, the good qualitative agreement (mainly contrast peak position and peak value) between the calculated and measured results of metamaterials indicates that our condition settings and parameter settings of simulation are valid. The S-parameter inversion method is used to extract the effective parameters of metamaterials, and obtained the electromagnetic field intensity distribution in the resonance frequency of metamaterial, explore the physical mechanism.The main contents of this paper are as follows:1. The basic principles of numerical simulation and modeling software have been introduced in this paper. At the same time, different structural design of MDM metamaterial samples have been experimental prepared.2. The influence of lattice constant of circular holes array MDM metamaterial on the optical transmission spectrum and negative refraction has been numerical studied. The low-frequency transmission peak of metamaterial abnormal increased with the decreased of the lattice constan, and the physical mechanism is the impedance matching. The negative refractive band blue-shifted with decreasing lattice constant decreased. For the rectangular holes array MDM metamaterials, by comparing the measurement and simulation transmittance, the condition settings of our simulation work is proved validity. By increasing the length of the rectangular hole, the main transmission peak and low peak transmission peaks have increased, while peaks appear redshifted. The absolute value of the negative refractive index negative refractive bandwidth decreases with increasing length in the range of low-frequency transmission peak.3. The effects of different shape of holes on the MDM electromagnetic properties of metamaterials have been studied. The low-frequency transmission peak amplitudeof cross-shaped hole reaches a maximum under the same condition. The circular holes array MDM metamaterials obtains the maximum negative refractive index. However, the negative refraction bandwidth of the rectangular holes array is biggest. The effects of the sub-structure on the metamaterial electromagnetic properties have been studied. By changing the distance in the longitudinal direction between the metal and the rectangular holes arrays, the interference and coupling strength between the LSP modes can be adjusted, thereby modulating the electromagnetic properties of metamaterials.4. The influence of the thickness and dielectric constant of dielectric layer on the optical properties of rectangular holes arrays metamaterials have been studied. The amplitude of the low frequency transmission peaks of metamaterial reaches the maximum with ε= 4 due to achieve impedance matching condition. With the increased of the thickness of the dielectric layer, the negative refractive index and negative refractive bandwidth increases. By using numerical fitting method, there is a similar linear variation between the dielectric layer thickness with a negative refractive index metamaterials.5. A broad stop-band metamaterials filter with CRR structure in the THz regime has been designed and a broad stop-band can be obtained through this structure. By calculating the filter near-field intensity distribution of the electric field intensity and current, it can be found that the physical mechanism is the plasmonic hybridization of inward coupling mode and adjacent unit cells coupling resonance mode lead to the stop-band broader. It is found that the filter is not sensitive to the metal but is very sensitive to the dielectric constant of the dielectric layer. A modified double fishnet structure metamaterial has been studied and a broad pass-band can be obtained. It can be found that perfect impedance matching leas to the broad pass-band. By increasing the main air hole diameter, the transmission bandwidth of metamaterial filter is increased, but the average transmittance is decreased. Reducing the thickness of the dielectric layer, the pass-band will be broader. Finally, the design of an improved double fishnet structure metamaterial pass-band filters has been designed and the effectiveness of the design was verified through simulation and experiment. The metamaterial filter can be obtained a pass-band from 90.0 to 105.0THz. The main physical mechanism is the metamaterial to get a perfect impedance matching within the transmission band range...
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