Formation of subwavelength periodic structures on tungsten induced by ultrashort laser pulses.

Institute of Optics, Information and Photonics, Max-Planck Research Group and University Erlangen-Nuremberg, 91058 Erlangen, Germany.
Optics Letters (Impact Factor: 3.18). 08/2007; 32(13):1932-4. DOI: 10.1364/OL.32.001932
Source: PubMed

ABSTRACT The evolution of surface morphology of tungsten irradiated by single-beam femtosecond laser pulses is investigated. Ripplelike periodic structures have been observed. The period of these ripples does not show a simple relation to the wavelength and angle of incidence. The orientation of ripples is aligned perpendicularly to the direction of polarization for linearly polarized light. Surprisingly, we find that the alignment of the ripple structure turned left or right by 45 degrees with respect to the incident plane when using right and left circularly polarized light, respectively. The period of the ripple can be controlled by the pulse energy, the number of pulses, and the incident angle. We find a clear threshold for the formation as a function of pulse energy and number of pulses. The mechanism for the ripple formation is discussed, as well as potential applications in large-area structuring of metals.

1 Bookmark
  • [Show abstract] [Hide abstract]
    ABSTRACT: Formation of self-induced gratings on a metal surface scanned by a focused femtosecond laser beam has been investigated. It is experimentally shown that application of femtosecond IR radiation allows one to form more ordered self-induced gratings as compared with the gratings formed by visible light. The dependence of the tilt of grating lines with respect to the beam polarisation direction on the distance between tracks and the beam motion direction in adjacent tracks is analysed. Formation of two-dimensional periodic gratings during double laser beam passage along the same trajectory but with a small difference in the beam polarisation directions has been found for the first time.
    Quantum Electronics 04/2014; 44(4):330. · 0.82 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The large-scale uniform self-organized ripples are fabricated on fluorine-doped tin oxide (FTO) coated glass by femtosecond laser. They can be smoothly linked in a horizontal line with the moving of XYZ stage by setting its velocity and the repetition rate of the laser. The ripple-to-ripple linking can also be realized through line-by-line scanning on a vertical level. The mechanism analysis shows that the seeding effect plays a key role in the linking of ripples.
    Chinese Physics B 09/2014; 23(9). · 1.39 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Fundamental mechanism of femtosecond-laser-induced periodic surface nanostructure formation has been investigated under the condition using superimposed multiple shots at lower fluence than the single-pulse ablation threshold. With increasing the shot number of low-fluence fs-laser pulses, the periodic nanostructure develops through the bonding structure change of target material, the nanoscale ablation with optical near-fields induced around the high curvatures, and the excitation of surface plasmon polaritons (SPPs) to create the nano-periodicity in the surface structure. It is confirmed that non-thermal interaction at the surface plays the crucial role in the nanostructure formation. Based on the mechanism, we have demonstrated that the periodic nanostructure formation process can be controlled to fabricate a homogeneous nanograting on the target surface, using a two-step ablation process in air. The experimental results obtained represent exactly the nature of a single spatial standing SPP wave mode that generates periodically enhanced near-fields for the nanograting formation. The calculated results for a model target reproduce well the nanograting period and explain the characteristic properties observed in the experiment.
    Applied Physics A 12/2013; 114(1). · 1.69 Impact Factor


Available from