Lasing in dark and bright modes of a finite-sized plasmonic lattice

• Published in: Nature communications 2017-01, Vol.8 (1), p.13687-13687, Article 13687
• Main Authors: Hakala, T. K., Rekola, H. T., Väkeväinen, A. I., Martikainen, J.-P., Nečada, M., Moilanen, A. J., Törmä, P.
• Format: Article
• Language: English
• Subjects: 142/126; 639/624/1020; 639/624/400; 639/925/927/1021; Arrays; Humanities and Social Sciences; multidisciplinary; Nanoparticles; Radiation; Science; Science (multidisciplinary); Silver
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms13687

Lasing at the nanometre scale promises strong light-matter interactions and ultrafast operation. Plasmonic resonances supported by metallic nanoparticles have extremely small mode volumes and high field enhancements, making them an ideal platform for studying nanoscale lasing. At visible frequencies, however, the applicability of plasmon resonances is limited due to strong ohmic and radiative losses. Intriguingly, plasmonic nanoparticle arrays support non-radiative dark modes that offer longer life-times but are inaccessible to far-field radiation. Here, we show lasing both in dark and bright modes of an array of silver nanoparticles combined with optically pumped dye molecules. Linewidths of 0.2 nm at visible wavelengths and room temperature are observed. Access to the dark modes is provided by a coherent out-coupling mechanism based on the finite size of the array. The results open a route to utilize all modes of plasmonic lattices, also the high- Q ones, for studies of strong light-matter interactions, condensation and photon fluids. Plasmonic dark modes are promising candidates for lasing applications. Here, Hakala et al . show lasing at visible wavelengths in dark and bright modes of an array of silver nanoparticles combined with optically pumped dye molecules, opening up a route to utilization of all modes of plasmonic lattices.