微波全介质超常媒质中多介质单元耦合诱导的透明效应机理与应用研究

Recently, the low loss metamaterial is achieved by using near field coupling induced electromagnetically induced transparence (EIT) effect in all-dielectric metamaterial, which has received increasing attention. However, the low loss and broadband slow light effect can’t be realized owing to the limitations of the bandwidth, the transmittance and the highest group index. In this program, the study of the mechanism of broad transparency effect induced by couplings between multiple dielectric units in microwave all-dielectric metamaterial is proposed. First of all, when multiple resonance units work together, the mechanism of all-dielectric metamaterial realizing the broadband and high group index is investigated by using the Mie scattering theory, equivalent medium theory and equivalent circuit theory. Second, the influences of different coupling ways between multiple resonant units on the bandwidth and dispersion characteristic for metamaterial are investigated. Moreover, the construction method of all-dielectric EIT metamaterial with wide bandwidth is proposed, and the fabrication and testing of the experimental samples are also accomplished. Finally, the all-dielectric EIT metamaterial is used in optimized designs of the microstrip antenna and the rectangular waveguide, which confirms its effectiveness in improving the performance of microwave device. The research results of this program are expected to solve the contradictory problem between bandwidth and group index in all-dielectric EIT metamaterial, which provides a solid theoretical foundation and an effective realization method for polarization controller and asymmetric transmitter at microwave frequencies and slow light devices in optical regimes.

近年来，在全介质超常媒质中利用近场耦合诱导的电磁感应透明效应（英文缩写为EIT）实现低损耗超常媒质，受到了日益关注。然而，受带宽、透波率以及最高群指数的限制，无法实现低损耗宽频带慢光效应。本项目提出研究微波全介质超常媒质中多介质单元耦合诱导宽频带透明效应机理。首先，利用Mie散射理论、等效媒质理论和等效电路理论研究多个谐振单元共同作用时全介质EIT超常媒质实现宽频带、高群指数的机理；其次，研究多谐振单元之间的不同耦合方式对超常媒质带宽、色散特性的影响，提出宽频带全介质EIT超常媒质构造方法，并完成实验样品的加工、测试；最后，将全介质EIT超常媒质应用于微带天线和矩形波导的优化设计中，以证实其在改善微波器件性能中的有效性。本项目的预期研究成果有望解决目前全介质EIT超常媒质带宽和群指数的矛盾等问题，为微波段极化控制器、非对称传输器以及光频段慢光器件的实现提供坚实的理论依据和有效的实现手段。

随着超介质研究的不断发展，超介质的损耗问题日渐凸显出来。目前，在全介质超介质中利用近场耦合诱导的电磁感应透明效应（英文缩写为EIT）实现低损耗超介质，受到了日益关注。然而，受带宽、透波率以及最高群指数的限制，无法实现低损耗、宽频带慢光效应。为了解决上述问题，本项目研究了微波全介质超介质中多介质单元耦合诱导宽频带透明效应机理。首先，利用Mie散射理论、等效媒质理论和等效电路理论研究了多个谐振单元共同作用时全介质EIT超介质实现宽频带、高群指数的机理；其次，提出了低损耗全介质EIT超介质、极化无关全介质EIT超介质和基于石墨烯的可调谐全介质EIT超介质；最后，将全介质EIT超介质应用于圆极化天线、电磁开关、电磁二极管以及完美吸收器等微波器件与天线的优化设计中，证实了其在改善微波器件与天线性能中的有效性。此外，我们还完成了基于环偶极子谐振的低损耗EIT超介质、风车状极化无关EIT超介质、磁性EIT超介质和基于石墨烯的THz可调谐EIT超介质的构造，并研究了超介质在基于液晶控制的漏波天线、基于液晶的新型电控平面阵列天线以及有源石墨烯超介质吸收器等方面的应用。本项目的研究成果可以解决目前全介质EIT超介质的损耗大、带宽窄等问题，为微波段极化控制器、非对称传输器以及光频段慢光器件的实现提供坚实的理论依据和有效的实现手段。