Multiple pulse heating cycles during the enclosed laser ablation of a laminated metallized polymer

A vacuum-deposited aluminium layer (about 20nm) is sandwiched between two layers of laminated oriented polyporpylene (OPP) film whose thickness varies from 20 to 40 μm. Selected areas of this sealed system were transparentised by the rearrangement of the aluminium layer without breaking the seal or causing damage to the OPP film using a 75 W Q-swiched neodymumdoped yttrium aluminium garnet laser. This paper investigates the effecst of the laser repetition with changes in experimentally produced laser tracks.