Barbara A, Le Perchec J, Collin S, Sauvan C, Pelouard J-L, López-Ríos T, Quémerais P
Institut Néel, CNRS et Université Joseph Fourier, Grenoble, France.
Opt Express. 2008 Nov 10;16(23):19127-35. doi: 10.1364/oe.16.019127.
We study the light localization on commensurate arrangements of deep metallic sub-wavelength grooves. We theoretically show that as the degree of commensuration tends to an irrational number new light localization states are produced. These have properties close to that reported for hot spots on disordered surfaces and are not permitted for simple period gratings. Existence of these new resonances is experimentally provided in the infra-red region by reflectivity measurements performed on two commensurate samples with respectively two and three slits per period. Manipulations of these hot spots which can be controlled from far-field could be used for high sensitivity spectroscopy applications.
我们研究了深度金属亚波长凹槽的相称排列中的光局域化现象。我们从理论上表明，随着相称度趋于无理数，会产生新的光局域化状态。这些状态的特性与无序表面上热点所报道的特性相近，而简单周期光栅则不允许出现这种情况。通过对两个相称样品进行反射率测量，在红外区域通过实验证实了这些新共振的存在，这两个样品分别每周期有两条和三条狭缝。这些可从远场控制的热点操控可用于高灵敏度光谱应用。
