Universal saturation behavior in the transient optical response of plasmonic structures

Quantitative Ultrafast Electron‐Temperature Dynamics in Photo‐Excited Au Nanoparticles

“…Also, the inhomogeneous broadening effects in the sample, arising from the dispersion of size inherent in the self-organized fabrication process, was mimicked by increasing the Drude damping of gold. Similar to what observed in previous studies, [62,63] this approach enables one to correctly reproduce the broadening of the extinction spectrum, but at the expense of an overestimation of the absorption contribution by approximately a factor of 2. Moreover, in the low temperature regime of our experiments, the imaginary part of gold permittivity is lower than at room temperature, [64] which is another possible reason why our calculations overestimates absorption.…”

Light–heat conversion dynamics in highly diversified water-dispersed hydrophobic nanocrystal assemblies

“…2 A and B for visible and near-infrared probing, respectively. On the initial timescale of 10 ps, the transient signal resembles the typical ∆T /T map recorded for plasmonic nanoparticles [spheres (28) or rods (29,30), for example]. In particular, the map cross-sections at early time delays (black and red traces in Fig.…”

“…In particular, the map cross-sections at early time delays (black and red traces in Fig. 2A, Bottom) show the characteristic transient spectra of isolated NCs which are dominated by shift and broadening of the plasmonic resonances (30). Moreover, these spectra exhibit a decay constant of a few picoseconds ( Fig.…”

Thermometric Calibration of the Ultrafast Relaxation Dynamics in Plasmonic Au Nanoparticles

“…52 ps, T bath = 356 K), until they almost overlap, within experimental uncertainty (Fig.3(c), τ = 300ps, T bath = 327 K) .…”

“…For the plasmonic response of the nanostructures we adopted a simplified approach in which the individual nanoparticles are treated as isolated oblate nanoellipsoids in the quasi-static limit in a homogeneous environment with effective refractive index n e . 52 To mimick the red shift and broadening of the plasmonic resonance arising from interparticle couplings and inhomogeneities along the sample, we took n e and the RT Drude damping constant of gold permittivity, Γ, as fitting parameters. The optical nonlinearity of gold was modeled according to the same approach reported in previous papers, including electronic and lattice heating effects being responsible to the subsequent modulation of The simulations enabled us to explore the validity of a thermometric calibration also for very high pump fluences, approaching the damage threshold.…”