New optical coatings are currently developed to mitigate the shockwave generated by nanosecond lasers in high-power laser systems such as the MegaJoule laser (LMJ). These shockwaves seem responsible for the damage growth observed on optical components. A possible solution for shockwave mitigation is using ormosil (organically modified silicate) coatings made by the sol–gel method with thicknesses of a few microns. Unfortunately, the sol–gel solution exhibits a viscous behavior, and thus, the deposited layers are heterogeneous in thickness. An experimental ellipsometer has been designed to measure this heterogeneity and highlight the viscoelastic properties of the layers responsible for self-healing effects that were observed when these layers were scratched. This ellipsometer allows us to know the refractive index of the coating and therefore its density. Density and thickness are the two essential parameters for determining the speed of sound and the modulus of elasticity of the layer, which indicate the ability of the layer to attenuate more or less elastic waves or shock waves.

Fano resonances in plasmonic nanostructures, generated by the spectral interference between a broad resonance or continuum and a narrow resonance, have attracted significant interest in recent literature. Herein, by introducing a nanodisc next to a nanoring via electron beam lithography, a set of Fano resonances for such a ring‐disc‐pair (RDP) hybrid is confirmed through coupling between the dipolar disc mode and different multipolar bonding ring modes. Furthermore, the influence of the RDP's geometric dimensions on the dark‐field scattering spectra is experimentally studied, indicating that the contrast ratio of Fano resonances can be improved by optimizing the ring/disc sizes and narrowing the gap in accordance with previous studies. The disc size can also control the spectral locations of these Fano peaks ranging from the visible to the near‐infrared regime. In addition, by comparing the Fano resonances among a series of ring/split‐ring/rod structures with varying curvatures coupled to a neighboring disc in simulations, it is demonstrated that the RDP presents stronger sensitivity for the same gap distance and shows high‐quality Fano resonances compared with more common disc‐inside‐ring cavities in literature.

To characterize the heterogeneity thickness of thin films responsible of modifications of the wave surface, an ellipsometer at 633 nm was developed. These films are designed to improve the lifetime of the Megajoule laser (LMJ).

Phenotypic plasticity has important ecological and evolutionary consequences. In particular, behavioural phenotypic plasticity such as plastic foraging (PF) by consumers, may enhance community stability. Yet little is known about the ecological conditions that favor the evolution of PF, and how the evolutionary dynamics of PF may modulate its effects on community stability. In order to address these questions, we constructed an eco evolutionary model in which resource and consumer niche traits underwent evolutionary diversification. Consumers could either forage randomly, only as a function of resources abundance, or plastically, as a function of resource abundance, suitability and consumption by competitors. PF evolved when the niche breadth of consumers with respect to resource use was large enough and when the ecological conditions allowed substantial functional diversification. In turn, PF promoted further diversification of the niche traits in both guilds. This suggests that phenotypic plasticity can influence the evolutionary dynamics at the community-level. Faced with a sudden environmental change, PF promoted community stability directly and also indirectly through its effects on functional diversity. However, other disturbances such as persistent environmental change and increases in mortality, caused the evolutionary regression of the PF behaviour, due to its costs. The causal relationships between PF, community stability and diversity are therefore intricate, and their outcome depends on the nature of the environmental disturbance, in contrast to simpler models claiming a direct positive relationship between PF and stability.