The numerical design, synthesis and characterization of advanced colloidal structures and foams based on High Internal Phase Emulsions for application in plasmonics, nano- and macro- photonics has proven to be very attractive, especially in the fields of lasing and new single photon sources.
In this talk, we will report a review of our work in these domains and explain the salient features of the involved effects.
As such, i) we provide experimental evidence of plasmonic super-radiance of organic emitters grafted to Au@SiO2 nanospheres at room temperature. This observation of plasmonic super-radiance at room temperature opens questions about the robustness of these collective states against decoherence mechanisms which are of major interest for potential applications.
ii) We demonstrate both experimentally and theoretically how to manipulate strong coupling between the Bragg-plasmon mode supported by an organo-metallic array and molecular excitons in the form of J-aggregates dispersed on the hybrid structure . We observe experimentally the transition from a conventional strong coupling regime exhibiting the usual upper and lower polaritonic branches to a more complex regime, where a third nondispersive mode is seen, as the concentration of J-aggregates is increased. Owing to numerical simulations, we could confirm the presence of the third resonance and attribute its physical nature.
iii) We demonstrate lasing oscillation in Colloidal Photonic Crystals (CPCs) based on a defect mode passband effect . The spectroscopic measurements and theoretical simulations match well and reveal that the relatively low-threshold lasing exhibited by the structure can uniquely be attributed to the efficient coupling of the spontaneous emission of the dye to the defect mode of the CPC.
Finally, iV), we have numerically predicted and experimentally shown the coexistence and competition of random lasing (RL) and stimulated Raman scattering (SRS) in active disordered random media: foams based on silica HIPEs [3, 4]. We developed a simple model which includes both mechanisms coupled through diffusion equations. We found that the prevalence of a nonlinear mechanism over the other is determined by the degree of scattering. The competition was explained in terms of disorder-dependent pump depletion and fluorescence saturation.
 P. Fauché, C. Gebhardt, M. Sukharev, M., R. A. L. Vallée, Scientific Reports 7, 4107 (2017).
 K. Zhong, L. Liu, X. Xu, M. Hillen, A. Yamada, X. Zhou, N. Verellen, K. Song, S. Van Cleuvenbergen, R. Vallée and K. Clays, ACS Photonics 3, 2330-2337, (2016).
 N. Bachelard, P. Gaikwad, R. Backov, P. Sebbah and R. A. L. Vallée, ACS Photonics, 1(11), 1206–1211 (2014)
 P. Gaikwad, N. Bachelard, P. Sebbah, R. Backov and RAL Vallée, Advanced Optical Materials, 3(11), 1640–1651 (2015).