Origin of periodicity in nanostructuring on thin film surfaces ablated with femtosecond laser pulses

Abstract

We report physical processes responsible for the periodic nanostructure formation in femtosecond-laser ablation of thin film surfaces. It has been found that an initial random distribution of nanoscale ablation traces is periodically structured with an increase in superimposed laser pulses or fluence on diamond-like carbon film used as the target. The results show that the formation of periodicity can be attributed to the excitation of surface plasmon polaritons to induce the periodic enhancement of local fields in the surface layer. The estimated field period is in good agreement with the observed size of nanostructures.

Reduction of Friction of Metals Using Laser-Induced Periodic Surface Nanostructures

“…The ripple structure studied in this paper is thus known as low spatial frequency laser-induced periodic surface structure (LSFL) [37]. As mentioned above, the formation mechanism of LIPSS is still in debate and some issues need to be further investigated [30][31][32][33][34][35]37]. Figure 3 shows the surface topography and the cross-sectional surface line profile of the ripple structures on the AISI 304L steel surfaces.…”

“…In general, LIPSS with periods close to the laser wavelength are called low spatial frequency LIPSS (LSFL), while LIPSS with periods much smaller than the laser wavelength are referred to as high spatial frequency LIPSS (HSFL) [20][21][22][23][24][25][26][27][28][29][30]. Several mechanisms have been proposed to explain the formation mechanisms of LIPSS, such as interference mechanisms [31], excitation of surface plasmon polaritons [32], self-organization [33], second harmonic generation [34], and Coulomb explosion [35]. However, some issues still need to be clarified.…”

Nanograting formation through surface plasmon fields induced by femtosecond laser pulses

“…Those are concerned with self-organization of surface instability, 1,16 linear and/or nonlinear refractive index change, 3,7 Coulomb explosion, 4 second-harmonic generation, 5,17 nanoplasma formation, 18,19 optical near-fields, 20,21 and excitation of surface plasmon polaritons (SPPs) in the surface layer. 22,23 Some of these mechanisms should contribute to the observed periodic nanostructure formation in specific cases. However, there have been few experiments to successfully demonstrate or control the fundamental interaction process responsible for the nanostructure formation.…”

Periodic and uniform nanogratings formed on cemented carbide by femtosecond laser scanning

“…1 So far, several mechanisms have been proposed to explain the formation of nanogratings induced by femtosecond laser pulses, such as interference between the incident laser light and the surface scattered wave [17], self-organization [6], second harmonic generation (SHG) [8], excitation of surface plasmon polaritons [18], and Coulomb explosion [19] etc. However, it is suggested from our research that the surface plasmon polaritons (SPPs) excited by femtosecond laser irradiation can explain the formation of nanogratings in this paper [20,21].…”