Coherent linking of periodic nano-ripples on a ZnO crystal surface induced by femtosecond laser pulses

Abstract

We demonstrate the coherent linking of periodic nano-ripples formed on the surface of ZnO crystals induced by femtosecond laser pulses. By adjusting the distance between two laser scanning zones, the periodic nano-ripples induced by two separated laser writing processes can be coherently linked and the ZnO nanograting with much longer grooves is therefore produced. The length limitation of this kind of nanograting previously set by the laser focus size is thus overcome. The micro-Raman mapping technique is used to evaluate the quality of coherent linking, and the underlying physics is discussed. The demonstrated scheme is promising for producing large-size self-organized nanogratings induced by femtosecond laser pulses.

Laser-induced periodic surface structures on ZnO thin film for high response NO2 detection

“…In this work, the generation of HSFL with a periodicity of approxi mately 145 nm has been shown. This result is in agreement also with the observations of X. D. Guo et al [25,26] and M. Zamfirescu [27]. Regarding the stablished classification of HSFL in the work of J. Bonse [11], we suggest that the fabricated structures consist in type HSFL 1 which are mainly observed in dielectrics and semiconductors with a period smaller than half of the incident laser wavelength and a depth of a few tens of nanometers.…”

Fabrication of large-scale ripples on fluorine-doped tin oxide films by femtosecond laser irradiation

“…The fine ripples should be formed by the multi-angle diffraction of the multiple incident laser pulses on the intermediate nonsinusoidal surface grating. [17] As to the linking of ripples with the moving XY Z stage in a horizontal line, we believe that the seeding effect [18] and near field ablation effect [19] play the key roles. The focus spot is divided into two areas (see Fig.…”

“…4(d) and 2(c)), that is, the as-formed ripples affect distribution of the surface plasma density wave, so the adjacent-line ripples will be favored only if their orientation reinforces their own growth (seeding effect). [18] When the neighboring line interval reduces to 7 µm and 6 µm, part of the focus spots will overlap with the above line ripples (see Fig. 4(e)).…”

Growth of ZnO nanostructures by femtosecond laser irradiation of polycrystalline targets

“…The subsequent work by Sipe and coworkers [6,7] provided the initial basis for the comprehension of their formation mechanism. These periodic structures occur in all types of materials [8] and the details regarding their formation mechanism with respect to the specific material, and processing conditions are still a very active field of research [1,[9][10][11][12][13][14][15][16][17][18][19]. Two different kinds of LIPSS are usually observed in most materials: low and high spatial frequency LIPSS (LSFL and HSFL, respectively), with periods K of the order of the incident wavelength for LSFL or much smaller, typically K/4-K/6, for the HSFL.…”