Plasmon-exciton-polariton lasing
Plasmon-exciton-polariton lasing
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DOI：
10.1364/optica.4.000031
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发表时间：
2017-01-20
期刊：
影响因子：
10.4
通讯作者：
Rivas, Jaime Gomez
中科院分区：
文献类型：
--
作者：
Ramezani, Mohammad;Halpin, Alexei;Rivas, Jaime Gomez
金属纳米结构为产生低于衍射极限的相干光提供了一个工具包。基于等离子体激元的激光依赖于发射体(如有机荧光团)的布居反转以及等离子体共振提供的反馈。在这种被称为弱光-物质耦合的状态下，系统的辐射特性可以用珀塞尔效应来描述。分子激子与等离子体结构产生的电磁场之间强烈的光-物质耦合导致了被称为等离子体激子-激子-极化子(PEP)的混合准粒子的形成。由于这些准粒子的玻色子性质，激子-偏振子凝聚可以在比传统光子激光器更低的阈值功率下产生类激光发射。在这里，我们观察到在光泵浦有机系统中，具有低阈值的金属纳米粒子阵列中通过暗等离子体模式的PEP激光。有趣的是，尽管活性材料的量子效率降低，但通过增加光与物质的耦合程度来降低激光的阈值功率，突出了导致激光的超快动力学，即受激散射。这些结果展示了在开腔结构中探索激子-偏振子物理的独特的室温平台，并为这种片上激光器件与当前的光子学和有源超材料平面技术的集成铺平了道路。(C)2016年度美国光学学会
Metallic nanostructures provide a toolkit for the generation of coherent light below the diffraction limit. Plasmonic-based lasing relies on the population inversion of emitters (such as organic fluorophores) along with feedback provided by plasmonic resonances. In this regime, known as weak light-matter coupling, the radiative characteristics of the system can be described by the Purcell effect. Strong light-matter coupling between the molecular excitons and electromagnetic field generated by the plasmonic structures leads to the formation of hybrid quasi-particles known as plasmon-exciton-polaritons (PEPs). Due to the bosonic character of these quasi-particles, exciton-polariton condensation can lead to laser-like emission at much lower threshold powers than in conventional photon lasers. Here, we observe PEP lasing through a dark plasmonic mode in an array of metallic nanoparticles with a low threshold in an optically pumped organic system. Interestingly, the threshold power of the lasing is reduced by increasing the degree of light-matter coupling in spite of the degradation of the quantum efficiency of the active material, highlighting the ultrafast dynamic responsible for the lasing, i.e., stimulated scattering. These results demonstrate a unique room-temperature platform for exploring the physics of exciton-polaritons in an open-cavity architecture and pave the road toward the integration of this on-chip lasing device with the current photonics and active metamaterial planar technologies. (C) 2016 Optical Society of America