Abstract

Multi-focus parallel scanning can effectively increase laser fabrication throughput. However, the conventional approach of using a spatial light modulator (SLM) to generate multi-foci and scan this fixed number of foci with galvanometer scanners can only achieve a periodic scanning trajectory due to the low switching speed of the SLM. Here we demonstrate a multi-focus non-periodic scanning method for femtosecond lasers by using, instead, a fast-switching digital micromirror device (DMD) to generate a dynamic number of foci. The number of effective foci is quickly switched by introducing aberration to the undesired focus. In this way, the intensity allocated to each focus will not be affected by the number of foci, and a uniformity of 98% with different numbers of foci is achieved without adjusting the total laser energy. Finally, we validate the effectiveness of this scanning method by demonstrating corneal flap fabrication of porcine cornea in vitro.

© 2024 Chinese Laser Press