Department of Material Chemistry, Graduate School of Engineering, Kyoto University , Katsura, Nishikyo-ku 615-8510, Kyoto, Japan.
Nano Lett. 2013 Sep 11;13(9):4106-12. doi: 10.1021/nl4015827. Epub 2013 Aug 9.
A SPASER, short for surface plasmon amplification by stimulated emission of radiation, is key to accessing coherent optical fields at the nanoscale. Nevertheless, the realization of a SPASER in the visible range still remains a great challenge because of strong dissipative losses. Here, we demonstrate that room-temperature SPASER emission can be achieved by amplifying longitudinal surface plasmon modes supported in gold nanorods as plasmon nanocavities and utilizing laser dyes to supply optical gain for compensation of plasmon losses. By choosing a particular organic dye and adjusting the doping level, the resonant wavelength of the SPASER emission can be tuned from 562 to 627 nm with a spectral line width narrowed down to 5-11 nm. This work provides a versatile route toward SPASERs at extended wavelength regimes.
受激辐射放大表面等离子体激元（SPASER）的英文缩写，是在纳米尺度上获取相干光场的关键。然而，由于强耗散损耗，实现在可见光范围内的 SPASER 仍然是一个巨大的挑战。在这里，我们证明了通过放大金纳米棒中支持的纵向表面等离子体模式作为等离子体纳米腔，并利用激光染料提供光增益来补偿等离子体损耗，可以实现室温 SPASER 发射。通过选择特定的有机染料并调整掺杂水平，可以将 SPASER 发射的共振波长从 562nm 调谐到 627nm，光谱线宽缩小到 5-11nm。这项工作为扩展波长范围内的 SPASER 提供了一种通用途径。
