基于悬链线纳米粒子超构表面的线偏振光SPPs定向激发

SPPs directional excitation of linearly polarized light based on catenary nanoparticle metasurface

表面等离激元(Surface plasmon polaritons,SPPs)定向激发是片上集成光子系统研发的基础,利用悬链线超构表面来实现SPPs的定向激发调控是近年来的热点和前沿领域,但现有研究多针对圆偏振光,线偏振光SPPs的定向激发相对较少。本文设计了一个基于悬链线纳米粒子的超构表面来实现线偏振光SPPs定向激发。采用时域有限差分法计算了x偏振光入射下的光谱消光比曲线和电场分布,根据多级散射理论和惠更斯-菲涅尔原理解释了定向激发的物理机制。仿真结果显示,悬链线纳米粒子超构表面对线偏振SPPs的定向调控是有效的,峰值消光比可达27 dB(对应入射波长820 nm),10 dB以上带宽约为47 nm(798 nm~845 nm),该结果有助于悬链线多功能器件的研究与开发。

Surface plasmon polaritons(SPPs)directional excitation is the basis for the development of on-chip integrated photonic systems.And SPPs directional excitation based on the catenary metasurface is a hot and frontier field in recent years,however,the SPPs directional excitation with linearly polarized light is less than that of circularly polarized light.In this paper,we design a catenary nanoparticle metasurface to realize the SPPs directional excitation with linearly polarized light.The spectral extinction ratio curve and electric field distribution under the incident of x-polarized light are calculated with the finite difference time domain.The physical mechanism of SPPs directional excitation is explained according to the multi-level scattering theory and the Huygens-Fresnel principle.The simulation results show that the SPPs directional excitation with linearly polarized light based on the catenary nanoparticle metasurface is effective,and the peak extinction ratio is up to 27 dB(corresponding to the incident wavelength of 820 nm),and the bandwidth above 10 dB is about 47 nm(798 nm~845 nm).Therefore,these results are helpful for the research and development of the catenary multifunctional devices.