The topography of laser-induced ripple structures

The authors present results which show the topography of the laser-induced periodic surface structures formed upon samples of germanium, which had been irradiated at a wavelength of 248 nm, and fused quartz irradiated at 10.6 mu m. Surface profiles are obtained from phaseshifting interferometry measurements. A slight modification to a theory which models the development of the surface contour during resolidification of a molten surface can be successfully employed to explain their observations upon germanium. To explain the profiles obtained on fused quartz they suggest that plasma oscillations at the surface may be involved.