Abstract
By choosing proper conditions, an intense pulse laser can clean a surface effectively without any damage on a base material. We have studied the laser cleaning process under water by time-resolved imaging technique, which uses two Nd:YAG lasers and a CCD Camera. Stainless steel plates covered by oxide layer are used as samples. Laser cleaning in air and under water conditions are imaged. A shade streak is observed on the laser axis inside but not outside of shock front in water. Some images seems to show blow-off of the oxide layer but not so clear yet. Formation of a bubble at laser-irradiated position starts at about 10 μs, becomes larger and then vanishes at 700 μs.
