All-dielectric magnetic metasurface for advanced light control in dual polarizations combined with high-Q resonances.
All-dielectric magnetic metasurface for advanced light control in dual polarizations combined with high-Q resonances.
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DOI：
10.1038/s41467-020-19310-x
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发表时间：
2020-10-30
影响因子：
16.6
通讯作者：
Belotelov VI
中科院分区：
文献类型：
--
作者：
Ignatyeva DO;Karki D;Voronov AA;Kozhaev MA;Krichevsky DM;Chernov AI;Levy M;Belotelov VI
纳米结构磁性材料为亚纳秒和亚微米尺度的光操纵提供了一种有效的工具，并允许观察在光滑薄膜中根本不可能的新效应。对于许多具有实际意义的情况，观察双极化状态下的磁光强度调制至关重要。然而，迄今为止报道的纳米结构通常利用横向克尔效应，因此仅对p偏振光提供光调制。我们提出了透明磁性超表面的概念来解决这个问题，并展示了一种新的磁光调制机制。超薄铁石榴石平板上的铋取代铁石榴石纳米柱的二维阵列形成支持准波导模式激发的超表面。与等离子体结构相比，全介电磁性超表面表现出更高的透明度和优异的品质因数共振，随后光强度调制成倍增加。多种激发模式类型的存在可以实现先进的光控制：p 偏振和 s 偏振照明的透射率对介质磁化强度变得敏感，这在光滑的磁性薄膜中基本上是不可能的。所提出的超表面对于传感、磁力测量和光调制应用非常有前景。作者在铁石榴石薄膜上制造并研究了由二维铁石榴石亚波长纳米柱阵列制成的超表面。它表现出高品质因数共振，使透射光的光强度调制成倍增加，并具有对介质磁化强度敏感的 P 和 S 偏振的优点。
Nanostructured magnetic materials provide an efficient tool for light manipulation on sub-nanosecond and sub-micron scales, and allow for the observation of the novel effects which are fundamentally impossible in smooth films. For many cases of practical importance, it is vital to observe the magneto-optical intensity modulation in a dual-polarization regime. However, the nanostructures reported on up to date usually utilize a transverse Kerr effect and thus provide light modulation only for p-polarized light. We present a concept of a transparent magnetic metasurface to solve this problem, and demonstrate a novel mechanism for magneto-optical modulation. A 2D array of bismuth-substituted iron-garnet nanopillars on an ultrathin iron-garnet slab forms a metasurface supporting quasi-waveguide mode excitation. In contrast to plasmonic structures, the all-dielectric magnetic metasurface is shown to exhibit much higher transparency and superior quality-factor resonances, followed by a multifold increase in light intensity modulation. The existence of a wide variety of excited mode types allows for advanced light control: transmittance of both p- and s-polarized illumination becomes sensitive to the medium magnetization, something that is fundamentally impossible in smooth magnetic films. The proposed metasurface is very promising for sensing, magnetometry and light modulation applications. The authors fabricate and investigate the metasurface made of 2D iron-garnet subwavelength nanopillar array on a thin iron-garnet film. It exhibits high quality-factor resonances, leading to a multifold increase in light intensity modulation of the transmitted light with an advantage of P and S polarizations both sensitive to the medium magnetization.