A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation
A hybrid plasmonic waveguide for subwavelength confinement and long-range propagation
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DOI：
10.1038/nphoton.2008.131
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发表时间：
2008-08-01
期刊：
影响因子：
35
通讯作者：
Zhang, X.
中科院分区：
文献类型：
--
作者：
Oulton, R. F.;Sorger, V. J.;Zhang, X.
新兴的纳米光子学领域（1）解决了在远小于波长的尺度上操控光这一关键挑战。然而，目前可行的实用方法极少。表面等离激元极化激元（2,3）是实现亚波长光学限制（3 - 10）最有希望的候选者之一。然而，由于包括光损耗和严格的制造要求等实际问题（3,11 - 13），对长程表面等离激元极化激元的研究仅展示出与传统介质波导相当的光学限制。在此，我们提出一种将介质波导与等离子体激元学相结合的新方法。这种混合光波导由一根介质纳米线构成，该纳米线通过一个纳米级的介质间隙与金属表面隔开。间隙两侧的等离子体激元模式和波导模式之间的耦合实现了类似“电容器”的能量存储，从而允许在非金属区域进行有效的亚波长传输。通过这种方式，表面等离激元极化激元能够在具有强模式限制（范围从λ²/400到λ²/40）的情况下传播较长距离（40 - 150毫米）。这种方法与半导体制造技术完全兼容，并可能催生真正基于纳米级半导体的等离子体激元学和光子学。
The emerging field of nanophotonics(1) addresses the critical challenge of manipulating light on scales much smaller than the wavelength. However, very few feasible practical approaches exist at present. Surface plasmon polaritons(2,3) are among the most promising candidates for subwavelength optical confinement(3-10). However, studies of long-range surface plasmon polaritons have only demonstrated optical confinement comparable to that of conventional dielectric waveguides, because of practical issues including optical losses and stringent fabrication demands(3,11-13). Here, we propose a new approach that integrates dielectric waveguiding with plasmonics. The hybrid optical waveguide consists of a dielectric nanowire separated from a metal surface by a nanoscale dielectric gap. The coupling between the plasmonic and waveguide modes across the gap enables 'capacitor-like' energy storage that allows effective subwavelength transmission in non-metallic regions. In this way, surface plasmon polaritons can travel over large distances (40-150 mm) with strong mode confinement ( ranging from lambda(2)/400 to lambda(2)/40). This approach is fully compatible with semiconductor fabrication techniques and could lead to truly nanoscale semiconductor-based plasmonics and photonics.