Schwarz Simon, Rung Stefan, Esen Cemal, Hellmann Ralf
Opt Lett. 2021 Jan 15;46(2):282-285. doi: 10.1364/OL.415959.
We report on micromilling cavities into fused silica by a 1030 nm femtosecond laser using 2.17 GHz bursts. The milled cavities show an increased depth per layer for a higher number of pulses per burst while the ablation efficiency is also increased. The maximum ablation efficiency for the optimum fluence achieved in our experiments is 3.05// for a burst number of 10, which is 7.4 times higher than for the non-burst condition (0.41//). Furthermore, the ablation threshold for each sub-pulse is significantly reduced from 0.64/ for the non-burst condition to 0.15/ for 10 bursts. Beside the ablation efficiency, the surface roughness is also increased with the increasing burst number, while two ablation behaviors can be distinguished, namely, a gentle ablation regime for lower burst numbers and a coarse ablation regime, dominated by breaking out the surface rather than ablating it.
我们报道了使用2.17GHz脉冲串的1030nm飞秒激光在熔融石英中进行微铣削加工的情况。对于每个脉冲串中更高的脉冲数，铣削出的腔层深度增加，同时烧蚀效率也提高。在我们的实验中，对于10个脉冲串的最佳能量密度，最大烧蚀效率为3.05//，这比非脉冲串条件下（0.41//）高7.4倍。此外，每个子脉冲的烧蚀阈值从非脉冲串条件下的0.64/显著降低到10个脉冲串时的0.15/。除了烧蚀效率外，表面粗糙度也随着脉冲串数量的增加而增加，同时可以区分出两种烧蚀行为，即较低脉冲串数量时的平缓烧蚀状态和以表面破碎而非烧蚀为主的粗糙烧蚀状态。
