左手材料设计及透明现象研究进展

左手材料具有负的介电常数, 磁导率和折射率, 它与电磁波相互作用的规律与传统材料有本质的区别. 首先讨论了金属线点阵结构实现负介电常数和开口谐振环点阵结构实现负磁导率的内在 机理,综述了目前实现左手材料的设计与制备方法, 讨论了左手材料研究中能量如何定义以满足守恒律, 左手材料的宏观等效参数的确定, 以及影响左手材料负折射相对频带带宽的因素。最后对左手材料在光子隧道效应和电磁波透 明方面的应用进行了介绍，重点讨论了利用力学中的``中性夹杂'概念对电磁波透明的设计. 论文还探讨了声波左手材料的概念和物理意义, 介绍了用声波左手材料实现声波透明的方法.

ADVANCES IN LEFT-HANDED MATERIAL DESIGN AND TRANSPARENCY PHENOMENON

Left-handed materials(LHM)have negative permittivity,negative permeability,and negative re- fractive index.The propagation mechanism of electromagnetic waves in the LHMs is fundamentally different from that in conventional materials.This paper first discusses the intrinsic mechanisms for realizing negative permittivity and negative permeability,then the recent progress in the design and fabrication of LHMs is sum- marized.Various problems related to LHMs are discussed,including the definition of EM energy in an LHM, the retrieving method of effective parameters of LHMs,and the parameters influencing the relative bandwidth for negative refraction of LHMs.The photon tunneling effect and electromagnetic transparency phenomenon induced by LHMs are reviewed,the neutral inclusion concept in mechanics is particularly discussed for the transparency design.In the end,the physical meaning and realization of acoustic LHMs are briefly introduced, the acoustic transparency phenomenon is discussed by analogy with the electromagnetic counterpart.