Robust topologically protected transport in photonic crystals at telecommunication wavelengths
Robust topologically protected transport in photonic crystals at telecommunication wavelengths
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DOI：
10.1038/s41565-018-0297-6
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发表时间：
2019-01-01
影响因子：
38.3
通讯作者：
Litchinitser, Natalia M.
中科院分区：
文献类型：
--
作者：
Shalaev, Mikhail, I;Walasik, Wiktor;Litchinitser, Natalia M.
光子拓扑绝缘体提供了消除后向散射损耗和提高光通信系统效率的可能性。尽管付出了相当大的努力，理论上预测的强大的，无损的能量传输拓扑绝缘体在近红外频率下工作的直接实验演示仍然是失踪。在这里，我们结合联合收割机的平面硅光子晶体的属性和拓扑保护的概念，设计，制造和表征的光学拓扑绝缘体，表现出谷霍尔效应。我们表明，透射率是相同的光传播沿着一个直的拓扑接口和一个有四个急转弯。该结果定量地证明了由于结构的非平凡拓扑结构对后向散射的抑制。与光子拓扑绝缘体的其他实现相比，基于光子晶体的方法提供了显著的优点，例如较低的传播损耗、晶体板平面中传播的光的带隙的存在、较大的操作带宽、小得多的占用面积、与互补金属氧化物半导体制造技术的兼容性以及它允许在电信波长下操作的事实。
Photonic topological insulators offer the possibility to eliminate backscattering losses and improve the efficiency of optical communication systems. Despite considerable efforts, a direct experimental demonstration of theoretically predicted robust, lossless energy transport in topological insulators operating at near-infrared frequencies is still missing. Here, we combine the properties of a planar silicon photonic crystal and the concept of topological protection to design, fabricate and characterize an optical topological insulator that exhibits the valley Hall effect. We show that the transmittances are the same for light propagation along a straight topological interface and one with four sharp turns. This result quantitatively demonstrates the suppression of backscattering due to the non-trivial topology of the structure. The photonic-crystal-based approach offers significant advantages compared with other realizations of photonic topological insulators, such as lower propagation losses, the presence of a band gap for light propagating in the crystal-slab plane, a larger operating bandwidth, a much smaller footprint, compatibility with complementary metal-oxide-semiconductor fabrication technology, and the fact that it allows for operation at telecommunications wavelengths.