Abstract When an ultrathin silver nanowire with a diameter less than 100 nm is placed on a photonic band gap structure, surface plasmons can be excited and propagate along two side-walls of the silver nanowire. Although the diameter of the silver nanowire is far below the diffraction limit, two bright lines can be clearly observed at the image plane by a standard wide-field optical microscope. Simulations suggest that the two bright lines in the far-field are caused by the unique phase distribution of plasmons on the two side-walls of the silver nanowire. Combining with the sensing ability of surface plasmons to its environment, the configuration reported in this work is capable of functioning as a sensing platform to monitor environmental changes in the near-field region of this ultrathin nanowire.

中文翻译：

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具有亚衍射限制分离的表面等离子体远场光学成像

摘要 当直径小于100 nm的超薄银纳米线放置在光子带隙结构上时，表面等离子体可以被激发并沿银纳米线的两个侧壁传播。虽然银纳米线的直径远低于衍射极限，但通过标准的宽视场光学显微镜可以在像平面上清晰地观察到两条亮线。模拟表明，远场中的两条亮线是由银纳米线两个侧壁上等离子体的独特相位分布引起的。结合表面等离激元对其环境的传感能力，这项工作中报告的配置能够作为传感平台来监测这种超薄纳米线近场区域的环境变化。