Towards fast femtosecond laser micromachining of fused silica: The effect of deposited energy

Abstract

Femtosecond laser micromachining of glass material using lowenergy, sub-ablation threshold pulses find numerous applications in the fields of integrated optics, lab-on-a-chips and microsystems in general. Inthis paper, we study the influence of the laser-deposited energy on the performance of the micromachining process. In particular, we show that theenergy deposited in the substrate affects its etching rate. Furthermore, we demonstrate the existence of an optimal energy deposition value. These results are not only important from an industrial point-of-view but also provide new evidences supporting the essential role of densification and consequently stress-generation as the main driving factor promotingenhanced etching rate following laser exposure.