Spontaneous and artificial direct nanostructuring of solid surface by extreme ultraviolet laser with nanosecond pulses

Abstract

Nanostructuring can be either spontaneously appearing (such as laser-induced periodic surface structures, and diffraction patterns – for example, in windows of grid proximity-standing at the ablated target-surface) or artificially created (like – as we hoped – interference patterns) that can be in some extend controlled. Due to that a new interferometer (belonging to wave-front division category) with two aspheric mirrors has been developed. Each of these mirrors reflects approximately one half of incoming laser beam and focuses it into a point image. Both focused beams have to intersect each other, and in the intersection region an interference pattern was expected. However, the first tests showed that some other spontaneously appearing interference pattern with substantially larger fringe-pitch is generated. The origin of this idle interference pattern is discussed.

Contrasting behavior of covalent and molecular carbon allotropes exposed to extreme ultraviolet and soft x-ray free-electron laser radiation

“…This is very likely caused by a lack of back reflectivity of XUV/SXR radiation from smooth sample surfaces illuminated under normal incidence conditions. An absence of the spontaneously created ripples on FEL illuminated surfaces could be useful for imprinting a de-magnified pattern from a mask [33] and/or an interferometer [34].…”

Characterizing the Grating-like Nanostructures Formed on BaF2 Surfaces Exposed to Extreme Ultraviolet Laser Radiation

“…The experiment was performed using the CAPEX device in Prague, which is a source of intense XUV radiation (with a wavelength of 46.9 nm) with an output pulse energy of 200 µJ. A more detailed description of CAPEX apparatus can be found in papers published earlier [7,20,21]. The XUV laser beam was focused inside a vacuum interaction chamber by a Si/Sc multilayer spherical mirror (R = 2100 mm) with reflectivity 15%.…”

“…The Ne-like Ar capillary-discharge laser (CDL) represents a compact, handy device that emits intense monochromatic radiation with a wavelength of 46.9 nm delivered in nanosecond pulses [1]. The extreme ultraviolet laser promises great potential for use in the field of holographic imaging [2], microscopy [3] and materials processing [4][5][6][7][8][9][10] including nanostructure manufacturing, benefitting from the short wavelength of its radiation. For numerous applications it is important that even a single photon carries the energy that exceeds the band gaps and the cohesive energies of almost all common materials.…”

“…Sci. 2022, 12, 1251 2 of 8 wavefront of the laser beam (for such experiments with XUV-CDL radiation see refs [7][8][9][10]). In this article, we shall concentrate on the spontaneous LIPSS formation on XUV-CDL irradiated surfaces.…”