A practical technique for the generation of highly uniform LIPSS

Polarisation-dependent generation of fs-laser induced periodic surface structures

“…Other attempts to explain this deviation are related to optical parameter variations of the metal surface owing to the excitation of surface plasmons [6] and a possibly reduced phase velocity of the surface plasmons due to surface roughness [30]. Generally, the comparison of experimentally obtained literature values for stainless steel reveals a exp range between about 526 nm and 650 nm [2][3][4]6,24,31]. However, the corresponding LIPSS were all generated with ≈ 800 nm emitted by Ti:Saphire lasers leading to exp / ratios ranging from 0.71 to 0.81.…”

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.…”

“…With the development of laser technology, ripples can now be induced by different lasers with varied wavelengths and pulse widths. 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].…”

Triangular laser-induced submicron textures for functionalising stainless steel surfaces

“…Such large-area texturing has been investigated by employing different processing strategies, e.g. the use of moving discrete spot laser irradiation to merge LIPSS [25,26] or through pulse overlapping [18,[27][28][29][30]. High repetition rates combined with high scanning speed, in the order of MHz and m/s respectively, has also been shown to enable area processing with sufficient pulse fluence and pulse overlap to generate uniform LIPSS in one pass; the uniformity being then obtained by optimising the distance between scanned lines [29].…”

“…High repetition rates combined with high scanning speed, in the order of MHz and m/s respectively, has also been shown to enable area processing with sufficient pulse fluence and pulse overlap to generate uniform LIPSS in one pass; the uniformity being then obtained by optimising the distance between scanned lines [29]. However, potential local non-uniformities of LIPSS are known to occur as a result of preceding polishing step [28,31], grain boundaries [32] and surface defects [28].…”