Tuning Of Metamaterials And The Polarization Application

Metamaterials are artificial media designed to have novel electromagnetic properties often not found in naturally occurring materials. With the in-depth study of metamaterials, the concept is expanded. And the emphasis has changed from the basic characteristic of metamaterials to its applications.In this thesis, we mainly study the basic characteristic and applications based on metal split-ring resonator(SRR) and nanowire structures.Firstly, we study the electromagnetic response of SRR under the effect of incident light. Then, it is the factors that affects SRR resonant characteristic, including the cell size, interaction between unit structure and surrounding media.Second, we get active tuning of metamaterials using SRR structure by electrical control. When the reverse bias voltage changes from 0 v to-8v, the resonant wavelength shift about 250 nm. In addition, we also put forward a new control method, by changing the polarization direction of incident light to change the resonant wavelength, which doesn't need additional incentive source. The new way of tuning is applied to two-cut SRR structure that is more sensitive to the polarized light. When the polarization angle changes 60°, the resonant wavelength shift about 150 nm.In this thesis, we also study the polarization application of two-cut SRR and nanowires. First of all, we found that the two-cut SRR structure can be used as a polarization selector. It allows only specific polarization direction of light through and blocks the orthogonal one. Second, we mainly study two aspects of application based on metal nanowire structure. They are the encoded and display controllable metamaterials respectively. Two different configurations of metal nanowire can be encoded as “0”and “1”code respectively. Then the decoding is based on the different transmission intensity of light. When in display, the transmittance of light varies with the different configurations of\metal nanowires. So we can get the brightness and darkness state in corresponding position. Also, the display status can be modulated by changing the polarization direction of light.