Plasmonic enhancement of two-photon-excited fluorescence is not only of fundamental interest but also appealing for many bioimaging and photonic applications. The high peak intensity required for two-photon excitation may cause shape changes in plasmonic nanostructures, as well as transient plasmon broadening. Yet, in this work, we report on strong enhancement of the two-photon-excited photoluminescence of single colloidal quantum dots close to isolated chemically synthesized gold nanorods. Upon resonant excitation of the localized surface plasmon resonance, a gold nanorod can enhance the photoluminescence of a single quantum dot more than 10 000-fold. This strong enhancement arises from the combined effect of local field amplification and the competition between radiative and nonradiative decay rate enhancements, as is confirmed by time-resolved fluorescence measurements and numerical simulations.

中文翻译：

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单个金纳米棒的单量子点的两个光子激发的等离子体增强等离子体。

等离子体增强双光子激发的荧光不仅具有根本的意义，而且吸引了许多生物成像和光子应用。双光子激发所需的高峰值强度可能会导致等离激元纳米结构的形状变化，以及瞬态等离激元展宽。然而，在这项工作中，我们报告了单个胶体量子点的双光子激发光致发光的增强，该光致发光靠近分离的化学合成金纳米棒。在局部表面等离子体共振的共振激发下，金纳米棒可以将单个量子点的光致发光增强超过10000倍。这种强大的增强来自局部场放大以及辐射衰减率和非辐射衰减率增强之间的竞争的综合影响，