Laser Nano-Structuring of Pre-Structured Substrates

Laser nano-structuring of pre-structured Ni substrate using short and ultra-short laser pulses is experimentally studied. Prestructured samples were prepared using electron beam lithography with final periodic relief with period 300 -500 nm and sinusoidal profile. The morphology of laser-produced nanostructures strongly depends on the respective orientation of prestructured grating and polarization vector of the laser beam. Surface Electromagnetic Waves induced in Ni substrate that interfere with laser beam are strongly dumped if the polarization vector of laser light is perpendicular to the initial e-beam grating. The morphology of laser-produced nanostructures also depends on the laser fluence of the substrate. Laser nanostructuring of Ni using a phase plate in the laser beam results in very specific morphology of the irradiated surface. Keywords: laser ablation, LIPSS, nanostructures, surface electromagnetic waves