Surface corrugating direct laser writing of microstructures in ternary chalcogenide films using a continuous-wave super-bandgap laser

Direct laser writing using a tightly focused 442 nm continuous-wave laser was applied to corrugate the surface of ternary As-S-Se chalcogenide thin films with high spatial resolution. The topography of the emerging surface relief structures and analyses of the underlying photo thermal processes indicate that depending on the beam intensity and writing speed the formation mechanisms of the surface patterns are mainly based on photoexpansion caused by thermoelastic deformation, mass flow out of the region of the highest local intensity in the center of the exposing laser beam resulting from an induced surface tension gradient, and decomposition/vaporization processes generated by the local heating due to absorption of the laser light. Examples of written periodic pattern arrays demonstrate that direct laser writing is a very promising method for the fabrication of surface relief structures into ternary chalcogenide thin films.