Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1533116 | Optics Communications | 2016 | 4 Pages |
•The ultrafast thermal dynamics is proposed for explaining nano-ripples formation.•The interplay of the electron diffusion and electron–phonon coupling are responsible for regulating nano-ripples formation.•The pulse-to-pulse relevance coupling into target material can explain nano-ripples contrast modulation.
The ultrafast thermal dynamics of nano-ripples formation on gold film via ultrafast laser double pulses excitation is theoretically investigated by numerical simulations. The non-equilibrium thermal modulations with respect to the electron and phonon energy transfers within gold film is proposed for predicting the nano-ripples formation. It is revealed that the nano-ripples contrast on gold film surface can be well controlled via tuning the pulse energy ratio, pulse separation and pulse exchange of ultrafast laser double-pulse. It is attributed to the tunable energy transfer routes between the electron thermal diffusion and the electron–phonon coupling via tuning double pulses parameters. The study provides theoretical basis for producing high-contrast ripples for a wide range application in the fields such as high-absorptive solar cells, surface friction devices and super-hydrophobic surface.