Gain Media In Plasmonic Nanostructures: From Superradiance To Lasing

Hybridisation of quantum emitters and plasmonic nano-structures has attracted much attention over the last years, due to their interest in the design of plasmon-based nano-lasers [1,2] or to achieve long-range qubit... [ view full abstract ]

Hybridisation of quantum emitters and plasmonic nano-structures has attracted much attention over the last years, due to their interest in the design of plasmon-based nano-lasers [1,2] or to achieve long-range qubit entanglement [3,4]. Recent theoretical studies [5,6] suggest a plasmonic super-radiant mechanism to increase the rate of emitters, similar to Dicke super-radiance [7]. 

1. In this work, we provide experimental evidence of plasmonic super-radiance of organic emitters close to a metal nanosphere at room temperature. A silica shell acts as a spacer between the grafted emitters and the Au core. A single particle study performed on 1400 nanohybrids with controlled core sizes, spacers and numbers of grafted emitters shows that the emission rate dramatically increases with the numbers of emitters and as the emitters get closer to the core. This observation of plasmonic superradiance at room temperature opens questions about the robustness of these collective states against decoherence mechanisms which are of major interest for potential applications. 

2. We propose a new type of nanodevice, capable of both path-selectivity and anisotropic lasing that is based on loss-compensation and amplification by a localized plasmon polariton. The nano-device is a Y-shaped plasmonic nanostructure embedded in an anisotropic host medium with gain. The anisotropy leads to the path selectivity, an effect which is more pronounced once gain is included. Such a device is potentially realizable via bottom-up techniques. The path-selectivity may be coupled with activation of a rotation of the anisotropic host medium forinducing a light-guiding switching functionality. 

References

[1] J.G. Bohnet et al. Nature 484, 78–81(2012). [2] M.A. Noginov et al., Nature 460, 1110–2 (2009). [3] R. Kolesov et al., Nature Physics 5, 470–474 (2009).[4] A. Gonzalez-Tudela et al., Phys. Rev. Lett. 106, 020501 (2011).[5] V.N. Pustovitet al., Phys. Rev. Lett. 102, 077401 (2009).[6] D. Martín-Cano et al., Nano Letters 10, 3129–3134(2010).[7] R.H. Dicke. Phys. Rev. 93, 99-110 (1954).