Time-resolved optical microscopy of a laser-based forward transfer process

Matrix-assisted pulsed laser evaporation direct write was investigated by ultrahigh speed optical microscopy. A composite barium–zirconium titanate/α-terpineol layer was irradiated by 355 nm laser pulses with a 150 ns pulse width, and it was observed that material removal does not begin until after the end of the pulse $\text{(t>200\hspace{0.05em}}\mathrm{ns})$ and continues for 1 μs after the irradiation. The desorption plume consists of micron-size particles moving with a velocity of ∼0.2 km/s. The slow response is attributed to the combination of particle absorbers and highly viscous fluid. The ability to form continuous, pinhole-free coatings is due to slow coalescence of the particles.