In symmetric nano/micro metal slit structures, interference patterns are produced by counter-propagating surface plasmon polaritons (SPPs) in the the center of structures, which can be employed to improve the resolution of microscopy and surface etching and to realize particle trapping. This paper focuses on the shift of the SPP interference patterns in the symmetric arc slit structures. The excitation models with one incident beam and two incident beams are established and analyzed respectively, and methods to shift the SPP interference patterns via adjusting the tilt angle and initial phase of the excitation beams are compared. The FDTD simulation results show that these methods can precisely shift the SPP interference patterns in the symmetrical arc slits. Compared to the linear slits, the SPP waves arising from arc slits are more strongly focused, resulting in a stronger gradient force. The characteristics of stronger focus and dynamic shifting of the focal spot give the symmetric arc slit structure unique advantages in the capture and transfer of the Rayleigh metallic particle.

中文翻译：

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对称弧缝结构中表面等离激元极化子干涉图案的移动及其在瑞利金属粒子俘获中的应用。

在对称的纳米/微金属狭缝结构中，通过在结构中心反向传播表面等离激元极化子（SPPs）产生干涉图样，可用于提高显微镜和表面蚀刻的分辨率并实现粒子捕获。本文重点研究对称弧缝结构中SPP干涉图的移动。分别建立和分析了具有一个入射光束和两个入射光束的激发模型，并比较了通过调整激发光束的倾斜角和初始相位来改变SPP干涉图样的方法。FDTD仿真结果表明，这些方法可以精确地偏移对称弧缝中的SPP干涉图样。与线性缝相比 弧缝产生的SPP波被更强地聚焦，从而产生更强的梯度力。焦点更强和焦点动态移动的特性使对称弧缝结构在瑞利金属颗粒的捕获和转移方面具有独特的优势。