Quesada R, Martín-Cano D, García-Vidal F J, Bravo-Abad J
Opt Lett. 2014 May 15;39(10):2990-3. doi: 10.1364/OL.39.002990.
In this Letter we introduce a novel route for achieving negative-group-velocity waveguiding at deep-subwavelength scales. Our scheme is based on the strong electromagnetic coupling between two conformal surface plasmon structures. Using symmetry arguments and detailed numerical simulations, we show that the coupled system can be geometrically tailored to yield negative-index dispersion. A high degree of subwavelength modal confinement, of λ/10 in the transversal dimensions, is also demonstrated. These results can assist in the development of ultrathin surface circuitry for the low-frequency region (microwave and terahertz regimes) of the electromagnetic spectrum.
在本信函中，我们介绍了一种在深亚波长尺度实现负群速度波导的新途径。我们的方案基于两个共形表面等离子体结构之间的强电磁耦合。通过对称性论证和详细的数值模拟，我们表明耦合系统可以在几何上进行调整以产生负折射率色散。还展示了在横向尺寸上达到λ/10的高度亚波长模态限制。这些结果有助于开发用于电磁频谱低频区域（微波和太赫兹波段）的超薄表面电路。
