| Metamaterial, a kind of composite artificial material which is booming in recentyears, has special electromagnetism (EM) property. This kind of materials has theunique response mode that we cannot find in nature, so we could use it to design somekind of devices to manipulate EM waves, especially in terahertz regime, where thereis scarcely practical and efficient device. Until now, the wire-grid structure is theprimary polarization manipulation device in terahertz regime, which is commercial,but there are some defects, including the high cost, low efficient way to manipulatethe polarization and the fragility of the metal structures, et al. Based on these, Ipropose my studies, designs, fabrications, and experiments about the polarizationmanipulation of terahertz wave using the theory and research of metamaterials in thispaper. This paper mainly includes:1. Theoretically, I summarize and develop the related theories and ways todesign metamaterials to realize the manipulation of terahertz wave; elaborating thebasic physics theory and mathematical expression of polarized light, describing thepolarization from the aspect of physics and mathematics; analyzing the successfultheory models of metamaterials, including the equivalent circuit model, equivalentmedium theory and interference theory for multi-layer structures, and applying themto the models I designed successfully.2. Experimentally, I introduce the terahertz time-domain spectroscopy system,which is used to characterize the response of the metamaterial devices, including theprinciple of radiator and receiver; introducing the procedure of fabricating themetamaterials in micron dimension; elaborating the proposed narrowband terahertzpolarization rotator, narrowband terahertz polarization convertor, broadband terahertzrotator and broadband terahertz quarter-wave plate, including their design, experimentdata, simulation data, the underlying mechanism, the optimization design and theapplication prospects. |
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