Plume and jetting regimes in a laser based forward transfer process as observed by time-resolved optical microscopy

Matrix-assisted pulsed laser evaporation direct-write was investigated by ultra high-speed optical microscopy. A layer of viscous fluid was irradiated with 355 nm, 30 ns laser pulses in a laser forward transfer configuration. The fluid response as a function of fluence was studied, and several distinct regimes of behavior were observed: plume, jetting and sub-threshold. This work emphasizes the fundamental differences between laser forward transfer of solid-state materials and rheological fluids.