Time-resolved shadowgraph imaging of femtosecond laser-induced forward transfer of solid materials

The transfer of solid phase material by femtosecond laser-induced forward transfer (LIFT) at atmospheric pressure by a time-resolved shadowgraph technique is studied. The influence of laser fluence on transfer of material in solid, fragmented and molten state is investigated during femtosecond LIFT of initially solid layers of thermoelectric bismuth selenide (Bi2Se3), piezoelectric lead zirconate titanate (PZT) and magnetostrictive Terfenol-D. We report ejection velocities of ∼48 m/s and ∼34 m/s for intact transfer of ∼1.1 μm thick Bi2Se3 and ∼1.8 μm thick PZT respectively, and of ∼140 m/s for ∼0.5 μm thick Terfenol-D. During intact transfer, contrary to what has been reported so far, no shock wave above the substrate surface was observed.