Microscopic and spectroscopic imaging of laser-induced forward transfer and its application to material transfer

As a investigation of the process of laser-induced forward transfer (LIFT), the behaviors of atoms, thermally radiating hot droplets and comparatively cold droplets were observed by two-dimensional laser-induced fluorescence (2D-LIF), laser light scattering (LLS) and thermal radiation. The observations were done with different parameters such as ablation laser energy, film thickness and gas pressure. The condition for the deposition of smaller film was guided. On the other hand, as an application, material transfer by LIFT was experimented. Rhodamine 610 laser dye film, which was deposited on silica substrate by LIFT, emitted fluorescence with an excitation by a second harmonic wave of the Nd:YAG laser. Experimental observations show that the fluorescence intensity of the deposited film was dependent on the LIFT process condition. The optimum condition was attained with a 50 run thickness of the base gold film and 49 mJ/cm(2) of the ablation laser fluence and in vacuum condition.