Surface plasmon polaritons (SPPs) are widely used for surface micro/nanostructures detection. However, because of the limitations of the common SPPs excitation conditions, it is difficult to flexibly detect surface micro/nanostructures in the air without being limited by the substrate structure. In this paper, a new SPPs excitation structure is developed. This structure is a silver film covered hemi-microsphere. SPPs could be excited on the surface of the Ag film, and induce collective oscillations of free electrons on the substrate surface to generate periodic electromagnetic waves. The periodic electromagnetic waves can enhance the electromagnetic field around the surface micro/nanostructures, which could benefit the detection of those surface micro/nanostructures. This method could work in the air, and requires less of the sample structure, but also could move above the sample to achieve a large range of detection. Simulation experiment results demonstrate that this structure has a good detection effect. The maximum enhancement achieved for nanoparticles is 113-fold. This structure holds great potential for medical detection and biosensing.

中文翻译：

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银膜覆盖的半微球产生的SPP增强了表面微/纳米结构的检测

表面等离子体激元（SPP）广泛用于表面微/纳米结构检测。然而，由于普通SPPs激发条件的限制，很难不受基底结构的限制，灵活地检测空气中的表面微纳结构。本文开发了一种新的SPPs激励结构。该结构是银膜覆盖的半微球。 SPPs可以在Ag薄膜表面被激发，并引起基底表面自由电子的集体振荡，从而产生周期性电磁波。周期性电磁波可以增强表面微纳米结构周围的电磁场，有利于表面微纳米结构的检测。该方法可以在空气中工作，对样品结构要求较少，而且可以在样品上方移动，实现大范围的检测。仿真实验结果表明该结构具有良好的检测效果。纳米颗粒实现的最大增强为 113 倍。这种结构在医学检测和生物传感方面具有巨大的潜力。