Far-Field Wavefront Control of Nonlinear Luminescence in Disordered Gold Metasurfaces

We demonstrate the local optimization of nonlinear luminescence from disordered gold metasurfaces by shaping the phase of femtosecond excitation. This process is enabled by the far-field wavefront control of plasmonic modes delocalized over the sample surface, leading to a coherent enhancement of subwavelength electric fields. In practice, the increase in nonlinear luminescence is strongly sensitive to both the nanometer-scale morphology and the level of structural complexity of the gold metasurface. We typically observe a 2 orders of magnitude enhancement of the luminescence signal for an optimized excitation wavefront compared to a random one. These results demonstrate how disordered metasurfaces made of randomly coupled plasmonic resonators, together with wavefront shaping, provide numerous degrees of freedom to program locally optimized nonlinear responses and optical hotspots

Structure de verres de silicophosphate dopés europium : analyse par spectroscopie optique et simulation de dynamique moléculaire

National audienc

Characterization of Erbium-Doped Nanoparticles in Transparent Glass Ceramic Optical Fibres

We report on using nanometric mass spectroscopy and molecular dynamics modelling to characterize the composition and structure of self-grown erbium-doped nanoparticles in transparent glass ceramic optical fibres fabricated by modified chemical vapour deposition without post-ceramming

Europium site symmetry in sol gel silicophosphate glass : FLN spectroscopy and Molecular Dynamics simulation

International audienc

Molecular dynamics simulation and crystal field calculations of the Eu2O3-PbO-SiO2 glassy system submitted to long annealing time

The Eu2O3-PbO-SiO2 glassy system submitted to a long annealing time (100 ps) has been obtained by molecular dynamics calculations. The average of 87/86 sites of the Eu3 + ion with six/seven nearest neighbours are used to discuss the number of lines and the local symmetry of the luminescent site through the crystal field parameters, using the simple overlap model in the frame of the method of equivalent nearest neighbours. The magnitude of the [View the MathML source] Bq2(q = 0, 1, 2) and the non-negligible [View the MathML source] B44 and [View the MathML source] B46( [View the MathML source] B34, [View the MathML source] B36 and [View the MathML source] B66) lead to the indication of distorted C4h and C3i site symmetries of the six and seven nearest neighbours, respectively. We have then compared very satisfactorily our 7F1 sublevels calculations with those observed in the emission spectra of an Eu-borate glass annealed for 30 min and 17 h. This comparison is justified because the emission behaviour of europium ions in different glassy systems are honestly very similar. Further, the decrease observed in the 5D0→7F2/5D0→7F1 transition intensity ratio is a clear indication that the Eu3 + ion are nucleating a crystalline phase. Such satisfactory comparisons indicate that we have obtained a transparent glass-ceramics

Un potentiel adaptatif simple pour la modélisation par Dynamique Moléculaire de la séparation de phase dans un verre de silice binaire

National audienc

Simulation par dynamique moléculaire de la structure des verres dopés terre rare

National audienc