In this paper, the array periodical nanofocusing effect in a kind of nanoscale three-dimensional surface plasmon polariton (SPP) waveguide array is introduced. The refractive index of the dielectric layer in the three-dimensional SPP waveguide arrays has a parabolic distribution. The SPPs in the waveguide arrays show a periodical focusing effect as light illuminates on all waveguides. The oscillation propagating effect, which is similar to the photonic spatial Bloch oscillations in waveguide arrays but is fundamentally different from the Bloch oscillation effect in physics, is also realized as light illuminates on part of the waveguides of the arrays. The theoretical work is carried out by the coupled wave theory and is well demonstrated by the finite-difference time-domain numerical simulations.

中文翻译：

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纳米尺度三维表面等离子体激元波导阵列中的阵列周期纳米聚焦效应

本文介绍了一种纳米尺度的三维表面等离子体激元（SPP）波导阵列中的阵列周期纳米聚焦效应。三维SPP波导阵列中介电层的折射率具有抛物线分布。当光照射在所有波导上时，波导阵列中的SPP表现出周期性的聚焦效果。当光照射在阵列的部分波导上时，也实现了与波导管阵列中的光子空间布洛赫振荡相似但与物理学中的布洛赫振荡效应根本不同的振荡传播效应。理论工作是通过耦合波理论进行的，并且通过时域有限差分数值模拟得到了很好的证明。