Li Jiaqi, Zhang Yuan, Jin Renchao, Wang Qianjin, Chen Qian, Dong Zhenggao
Opt Lett. 2014 Dec 1;39(23):6683-6. doi: 10.1364/OL.39.006683.
Plasmon toroidal mode is a unique electromagnetic resonance that cannot be expanded by general electronic or magnetic multipoles. Usually, this mode excitation needs complicated nanostructures, which is a challenge for sample fabrications, especially for nanodesigns with optical resonant frequencies. In this work, we designed a circular V-groove array and studied its toroidal-mode excitation by angle-resolved reflection experimentally and numerically. Our results show that a plasmon toroidal mode around wavelength 700 nm can be excited in this simple nanostructure for incident angles larger than 20°. Compared to reported papers, our design can realize the optical excitation of plasmon toroidal mode, which is useful in high-sensitivity plasmon sensors.
表面等离子体环形模式是一种独特的电磁共振，无法通过一般的电或磁多极子进行扩展。通常，这种模式的激发需要复杂的纳米结构，这对样品制备来说是一个挑战，特别是对于具有光学共振频率的纳米设计。在这项工作中，我们设计了一种圆形V形槽阵列，并通过实验和数值模拟研究了其通过角分辨反射的环形模式激发。我们的结果表明，对于大于20°的入射角，在这种简单的纳米结构中可以激发波长约700 nm的表面等离子体环形模式。与已报道的论文相比，我们的设计能够实现表面等离子体环形模式的光学激发，这在高灵敏度表面等离子体传感器中具有应用价值。
