At the conference, we will present our recent efforts in the area of plasmons and hot electrons.
Absorption-loss measurement in nanostructured films with hot electrons. The knowledge of the absorption losses (the local heat source term in the thermal diffusion equation) in devices using metal films is crucial for most components. The local heat generated by plasmon decays cannot be directly measured with classical low-temporal resolution techniques because these techniques provide temporally- and spatially-broadened versions of the local heat source (after heat diffusion in the metal). We have used the permittivity changes induced by hot electrons to measure the absorption losses in metal films incorporating subwavelength apertures. The measurements performed in a temporal scale of 500 fs, much smaller than the characteristic diffusion times of electrons and phonons, shows quantitative agreement with theoretical results [1].
Generation of hot electrons in plasmonic addiabatic tapers. Devices capable of generating hot-electrons with good efficiencies in nanoscale spots are likely to be highly desirable [2] for future prospects in the emerging field of plasmon-induced hot carrier generation. At the conference, we will show measurements of the permittivity variations induced by the hot-electron energy relaxation in the electron gas of adiabatic nano-focusing plasmon tapers. The variations that are collected ~100-fs after the plasmon absorption are expected to provide faithful images of the local heat source or equivalently of the density of hot-carrier generation
[1] O. Lozan, M. Perrin, B. Ea-Kim, J.M. Rampnoux, S. Dilhaire and P. Lalanne, "Anomalous light absorption around tiny apertures in metal films", Phys. Rev. Lett. 112, 193903 (2014). editor selection and focus in physics, http://physics.aps.org/articles/v7/52
[2] C. Clavero, Nature. Photon. 2014, review article.
stefan.dilhaire@u-bordeaux.fr