Near‐field mapping of surface polariton fields
Near‐field mapping of surface polariton fields
复制标题
表面极化子场的近场测绘
DOI：
10.1046/j.1365-2818.2001.00809.x
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发表时间：
2001
影响因子：
2
通讯作者：
S. Bozhevolnyi
中科院分区：
文献类型：
--
作者：
S. Bozhevolnyi
利用收集近场光学显微镜成像的一般方法，推导了在弱导单模光纤端接具有轴对称性的探针针尖的情况下，振幅耦合系数的对称关系。结果表明，对于对称的检测配置，耦合矩阵的六个元素可以表示为只有三个独立的耦合系数。得到的关系进一步应用于描述近场映射的表面等离子体激元（SPP）场。我证明，对于对称检测配置，近场光学图像反映了平行于表面平面的SPP场分量的强度分布，即使强垂直分量也被检测到。这一结论得到了数值模拟的支持，数值模拟阐明了光纤探头的对称性对所得近场光学图像的影响。近场光学图像模拟散射系统的SPP微光学和本地化的典型。研究发现，探测结构中存在的非对称性增加了垂直场分量的贡献，并导致图像接近相应的SPP强度分布。
Using the general approach to image formation in collection near‐field optical microscopy, I derive the symmetry relations for the amplitude coupling coefficients in the case of a weakly guiding single‐mode fibre terminated with a probe tip possessing axial symmetry. It is shown that, for the symmetrical detection configuration, six elements of the coupling matrix can be expressed by using only three independent coupling coefficients. The obtained relations are further applied to describe near‐field mapping of surface plasmon polariton (SPP) fields. I demonstrate that, for the symmetrical detection configuration, the near‐field optical image reflects the intensity distribution of the SPP field components parallel to the surface plane, even though the strong perpendicular component is also being detected. This conclusion is supported with numerical simulations that elucidate the influence of symmetry of the fibre probe on the resulting near‐field optical image. The near‐field optical images simulated for scattering systems typical for SPP microoptics and localization are presented. It is found that the presence of asymmetry in the detection configuration increases the contribution of the perpendicular field component and results in the images approaching the corresponding SPP intensity distributions.