Pourjamal Sara, Hakala Tommi K, Nečada Marek, Freire-Fernández Francisco, Kataja Mikko, Rekola Heikki, Martikainen Jani-Petri, Törmä Päivi, van Dijken Sebastiaan
Department of Applied Physics , Aalto University School of Science , FI-00076 Aalto , Finland.
Institute of Photonics , University of Eastern Finland , FI-80101 Joensuu , Finland.
ACS Nano. 2019 May 28;13(5):5686-5692. doi: 10.1021/acsnano.9b01006. Epub 2019 Apr 15.
We report on lasing at visible wavelengths in arrays of ferromagnetic Ni nanodisks overlaid with an organic gain medium. We demonstrate that by placing an organic gain material within the mode volume of the plasmonic nanoparticles both the radiative and, in particular, the high ohmic losses of Ni nanodisk resonances can be compensated. Under increasing pump fluence, the systems exhibit a transition from lattice-modified spontaneous emission to lasing, the latter being characterized by highly directional and sub-nanometer line width emission. By breaking the symmetry of the array, we observe tunable multimode lasing at two wavelengths corresponding to the particle periodicity along the two principal directions of the lattice. Our results are relevant for loss-compensated magnetoplasmonic devices and topological photonics.
我们报道了在覆盖有有机增益介质的铁磁镍纳米盘阵列中实现可见波长的激光发射。我们证明，通过将有机增益材料置于等离子体纳米颗粒的模式体积内，镍纳米盘共振的辐射损耗，尤其是高欧姆损耗都可以得到补偿。在泵浦通量增加的情况下，系统呈现出从晶格修饰的自发发射到激光发射的转变，后者的特征是具有高度定向性和亚纳米线宽的发射。通过打破阵列的对称性，我们观察到在对应于晶格两个主方向上粒子周期性的两个波长处出现可调谐多模激光发射。我们的结果与损耗补偿磁等离子体器件和拓扑光子学相关。
