The Study Of Ceramic-metal Hybrid Metamaterials' Nonlinear Electromagnetic Behavior

Metamaterials is artificial structure engineered with specific size smaller than the wavelength of interest which can achieve unusual electromagnetic responses that are not available in nature as the interaction of the resonant units.The metallic resonant units based on the surface current oscillations have been successfully applied on the designing of muti-properties metamaterials.However,the inherent Ohmic losses,the complex geometries especially in nanoscale and the difficulty to achieve the isotropic properties limit its development and application in high frequency.The dielectric metamaterials is gradually becoming the research focus on account of low-loss,simple configuration,feasibility of fabrication and versatile construction of isotropic metamaterials.Based on the nonlinear dielectric temperature effect and the local field enhancement,the enhanced nonlinear electromagnetic response to incident energy can be achieved.It is of significance for the reversible dynamic tunablity of metamaterials by studying the nonlinear response character to the incident power.This dissertation mainly includes the following aspects:(1)We study the nonlinear electromagnetic response to the incident power of single dielectric cubic,which forms magnetic dipole oscillation due to Mie resonance when the incident magnetic field is perpendicular that results to local field enhancement.Then,we theoretically and experimentally investigate the nonlinear response character of the hybrid metamaterials electromagnetically induced transparency effect consists of metallic wire which can be directly excited by the incident electric field and the same cubic.Both the Mie resonance and the EIT resonance frequency exhibit prominent blueshifts when the incident power increases,with the dynamic tunablity of groupdelay and transmission,furthermore,hysteretic transmission-incident field power loops is achieved.(2)The nonlinear frequency shift phenomenon under different incident powers of single dielectric wire which forms electric dipole oscillation due to Mie resonance when the incident electric field along with the wire under the condition of proper aspect ratio is experimentally studied.By assembling two parallel ceramic wires of different lengths,high Q and sharp Fanotype asymmetric transmission spectra emerge as a result of interference between the quadrupole and dipole modes.The enhanced local field due to Fano resonance enhances the nonlinear response and the groupdelay varies under different incident power.(3)Unlike previous reports where different size of dielectric resonators is essential to produce Fano resonance,with dielectric metamaterial pentamer composed of identical ceramic bricks which induced magnetically Fano resonance is presented,under external magnetic field excitation,central and outer dielectric bricks with identical size exhibit in-phase and out-of-phase magnetic Mie oscillations,corresponding to superradiant and subradiant modes,respectively.Meanwhile,we take the factors of the central cubic size,the distance of the central and outer dielectric bricks and ambient temperature into consideration to study their influence.This paper experimentally and theoretically studies the nonlinear response of dielectric metamaterials based on the mechanism of local field enhancement and dielectric temperature effect and achieves the tunablity of the groupdelay and the transmission.