A comparative schlieren imaging study between ns and sub-ps laser forward transfer of Cr

A comparative study of the effect of ultrashort (0.5 ps) and short (30 ns) pulses on the laser forward transfer of Cr is presented in this paper. The dynamics of the process was investigated by stroboscopic schlieren imaging for time delays up to 3 μs following the laser irradiation pulse. In contrast to the ns laser, the directionality of the ejected material is very high in the case of the sub-ps laser process. The narrow angular divergence (3°) of the sub-ps pulses permits the direct dynamic transfer of the material and opens up new application possibilities for the fabrication of high spatial resolution microstructures.