METHOD FOR SCANNING A PULSED LASER BEAM FOR SURFACE ABLATION

摘要

A fast and smooth scanning for achieving a uniform ablated surface without relying on any synchronization between the laser pulses and the scanner mirror positions. The scanning takes a series of close loops and the scanning speed on each loop is fine-tuned according to the perimeter of the loop. A uniform and close-packed pulse disposition along each loop can be achieved by multiple successive scans along the loop, while the consecutive pulses of a scan can be well separated. The scanning pattern is designed such that the energy distribution is uniform for every layer and the smoothness of the ablated surface remains substantially unchanged as the number of the layer increases.