Plume dynamics by thin film carbon target by YAG laser

摘要

Plume dynamics induced by the ablation of thin carbon film of 200 nm deposited on a polymethylmethacrylate (PMMA) substrate has been studied. Laser beam was focused from rear side through PMMA substrate. We call this special target 'thin film target'. Thin film target is found to achieve high-energy density states by absorbing the pulse laser energy. An Nd:YAG laser of infrared wavelength is used in this study due to the efficient absorption of energy by the ablated plasma plume. Ablation emission was observed by the high-speed streak camera. Plume is shown to be induced at the carbon film surface and also at the opposite PMMA surface. Several velocity groups are recognized in the plume. Stress waves in PMMA plate placed close to the thin film target was observed by the pulse laser shadowgraphy.