Generation of ribbons, helicoids, and complex Scherk surfaces in laser-matter interactions.

Motivated by a diversity of the shape instability phenomena in condensed-matter physics, we study the formation of elastic ribbon structures and transformation into helicoidal structures. Using the multipulse laser-matter interaction with the Co-coated surface, a one-dimensional high-density vortex-filament array has been created. Increasing the number of pulses, the oscillatory strain field causes the cascade of the shape transformations into structures of increasing topological complexity: vortex filaments into ribbons, into ribbon helicoids and tubular-ribbon helicoids, and then into short ribbon structures with the complex Scherk surface being identified.

Supercomplex wave-vortex multiscale phenomena induced in laser-matter interactions.

The interaction of laser light with a metal surface yields a complex configuration of point defects, e.g., droplets and holes and vortex microfilaments.

Determination of the refractive index of a-Si(1-x)C(x):H thin films from infrared absorption spectra.

The index of refraction of a-Si(1-x)C(x):H thin films obtained by dc magnetron sputtering was determined by means of IR absorption measurements. Structural and compositional changes that take place by increasing x make the film a mixture of different species, giving an effective value of the refractive index.