Apertureless near-field optical microscopy: Tip–sample coupling in elastic light scattering

作者：Markus B. Raschke, Christoph Lienau · 发表于：Applied Physics Letters · 年份：2003 · DOI：10.1063/1.1632023 · 被引用次数：195 · 研究领域：Near-Field Optical Microscopy、Integrated Circuits and Semiconductor Failure Analysis、Force Microscopy Techniques and Applications

For linear light scattering in apertureless scanning near-field optical microscopy, we have studied the correlations between the tip radius of the probe, signal strength, spatial resolution, and sample material. Pronounced variations of the near-field distance dependence on tip shape and dielectric function of the sample are observed. For very sharp metal tips, the scattered near-field signal decays on a 5 nm length scale. Despite this highly localized tip–sample coupling, the contrast is found to depend sensitively on the vertical composition of the sample on a length scale given by the penetration depth of the incident light. The resulting implications on the use of the technique as an analytic probe method are discussed.