ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona), Spain.
Nano Lett. 2012 Sep 12;12(9):4864-8. doi: 10.1021/nl3023912. Epub 2012 Aug 17.
Mapping the optical near-field response around nanoantennas is a challenging yet indispensable task to engineer light-matter interaction at the nanometer scale. Recently, photosensitive molecular probes, which undergo morphological or chemical changes induced by the local optical response of the nanostructures, have been proposed as a handy alternative to more cumbersome optical and electron-based techniques. Here, we report four-photon absorption in poly(methyl methacrylate) (PMMA) as a very promising tool for nanoimaging the optical near-field around nanostructures over a broad range of near-infrared optical wavelengths. The high performance of our approach is demonstrated on single-rod antennas and coupled gap antennas by comparing experimental maps with 3D numerical simulations of the electric near-field intensity.
绘制纳米天线周围的近场光响应是一项具有挑战性但不可或缺的任务，可用于在纳米尺度上设计光物质相互作用。最近，光敏分子探针已经被提出作为更繁琐的光学和电子技术的替代方案，这些探针由于纳米结构的局部光响应而发生形态或化学变化。在这里，我们报告了聚甲基丙烯酸甲酯（PMMA）中的四光子吸收，这是一种非常有前途的工具，可用于在近红外光波长范围内对纳米结构周围的近场光进行纳米成像。我们的方法通过将实验图谱与电场强度的 3D 数值模拟进行比较，在单棒天线和耦合间隙天线上证明了其出色的性能。
