Laboratoire Charles Fabry de l'Institut d'Optique, CNRS, Université Paris Sud, Campus Polytechnique, RD128, 91127 Palaiseau, France.
Phys Rev Lett. 2011 Jul 22;107(4):043903. doi: 10.1103/PhysRevLett.107.043903. Epub 2011 Jul 19.
We theoretically study fishnet metamaterials at optical frequencies. In contrast with earlier works, we provide a microscopic description by tracking the transversal and longitudinal flows of energy through the fishnet mesh composed of intersecting subwavelength plasmonic waveguides. The analysis is supported by a semianalytical model based on surface-plasmon coupled-mode equations, which provides accurate formulas for the fishnet refractive index, including the real-negative and imaginary parts. The model simply explains how the surface plasmons couple at the waveguide intersections, and it shines new light on the fishnet negative-index paradigm at optical frequencies. Extension of the theory for loss-compensated metamaterials with gain media is also presented.
我们从理论上研究了光频中的鱼网超材料。与早期的工作不同，我们通过跟踪能量在由相交的亚波长等离子体导波组成的鱼网中的横向和纵向流动，提供了微观描述。该分析得到了基于表面等离子体耦合模方程的半解析模型的支持，该模型为鱼网折射率提供了准确的公式，包括实部和虚部。该模型简单地解释了表面等离子体在波导交叉处如何耦合，并为光频中的鱼网负折射率范例提供了新的思路。我们还提出了具有增益介质的损耗补偿超材料的理论扩展。
