Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziadzka 5, 87-100 Torun, Poland.
Nanoscale. 2018 Jul 9;10(26):12841-12847. doi: 10.1039/c8nr04517h.
In this paper, we demonstrate remote activation and detection of the 2-photon up-conversion luminescence via surface plasmon polaritons propagating in a long silver nanowire. The hybrid nanostructure was assembled by locally depositing a submicron droplet of nanocrystal-containing colloidal solution on one of the ends of the metallic nanowire. When - using a classic confocal microscope - the second end of the nanowire, without the nanocrystals, is illuminated with infrared laser light, we observe strong emission from the same end. Therefore, it indicates that surface plasmon polaritons activated with infrared light at the second end of the nanowire propagate along it and can excite nanocrystals in the droplet at the opposite end. Subsequently, the excited nanocrystals up-convert the energy and by launching surface plasmon polaritons can guide the up-converted luminescence back to the starting point. The emergence of this effect is much more pronounced for a laser polarized along the nanowire. The spectral and temporal character of this emission reveals strong interactions between surface plasmon polaritons and electronic states of the nanocrystals. The details of local and non-local aspects of the effects of remote excitation and guiding of energy in a silver nanowire are elucidated using a unique experimental setup, based on two microscope objectives for spatial separation and control of both excitation and emission beams.
在本文中，我们通过在长银纳米线中传播的表面等离激元演示了 2 光子上转换发光的远程激活和检测。通过在金属纳米线的一端局部沉积含有纳米晶的胶体溶液的亚微米液滴来组装混合纳米结构。当使用经典的共焦显微镜时，用红外激光照射没有纳米晶的纳米线的第二端，我们观察到来自相同端的强发射。因此，这表明在纳米线的第二端用红外光激活的表面等离激元沿其传播，并可以在相对端的液滴中激发纳米晶。随后，受激纳米晶上转换能量，并通过发射表面等离激元将上转换光引导回起点。对于沿纳米线偏振的激光，这种效应更为明显。这种发射的光谱和时间特性揭示了表面等离激元和纳米晶的电子态之间的强烈相互作用。使用独特的实验装置阐明了银纳米线中远程激发和能量引导的局部和非局部效应的细节，该装置基于两个显微镜物镜，用于激发和发射光束的空间分离和控制。
