Femtosecond dynamics of the laser-induced solid-to-liquid phase transition in aluminum

Patterning of Aluminium thin film on polyethylene terephthalate by multi-beam picosecond laser

“…The measured ablation threshold here, F th ¼0.20 70.01 J cm À 2 is similar to the damage threshold measured by Kandyla [15], F th $ 0.21 J cm À 2 on Al film/glass using 40 fs pulses at 800 nm and close to that of Doerr [5] who measured a damage threshold, F th ¼ 0.18 J cm À 2 at τ p ¼ 2 ps pulselength and wavelength 400 nm on a 20 nm thick Aluminium film on fused silica. The similarity of these thresholds is interesting in spite of the differences in temporal pulselengths and wavelengths.…”

“…10 11 W cm À 3 K À 1 [4] is consistent with electron-lattice heating time τ e-ph of around a few ps. In fact, a study of the ultrafast dynamics of the solid-toliquid transition in a 1 mm thick Aluminium film using 40 fs pulses showed that this transition takes place within 1.5-2 ps, compatible with thermal melting [15].…”

Guiding heat in laser ablation of metals on ultrafast timescales: an adaptive modeling approach on aluminum

“…The highest value is obtained at the end of the sequence, a few ps after the maximum e-i non-equilibrium (marked as NE in figure 3(c)). As Al does not show strong optical variations as it makes the transition to the liquid phase [39], this points to an alteration of the properties related to the onset of the vapor phase. The gas-phase involvement is supported by the space evolution of the expanding matter on hundreds of nm, and it will be confirmed in the next paragraphs.…”

Ultrafast dynamics of bis (n-butylimido) perylene thin films excited by two-photon absorption

“…Note that as the delay time changes the shape of the Au-BuPTCD reflectivity spectra does not undergo significant changes. Reflectivity data at time delays less than 500 fs are not shown, as they tend to exhibit contributions from coherent artifacts during pulse overlap and from the vibration relaxation of the perylene molecules [4,21,22,28,29]. Figure 2b show normalized reflectivity, R/R 0 as a function of the time delay between the pump and probe pulses, for three selected probe wavelengths representing the three distinct regions observed in the transient spectrum of Fig.…”