GHz bursts in MHz burst(BiBurst) enabling high-speed femtosecond laser ablation of silicon due to prevention of air ionization  

作　　者：Kotaro Obata Francesc Caballero-Lucas Shota Kawabata Godai Miyaji Koji Sugioka 

机构地区：[1]RIKEN Center for Advanced Photonics,2-1 Hirosawa,Wako-shi,Saitama 351-0198,Japan [2]Department of Applied Physics,Tokyo University of Agriculture and Technology,2-24-16 Nakacho,Koganei,Tokyo 184-8588,Japan

出　　处：《International Journal of Extreme Manufacturing》2023年第2期208-214,共7页极端制造（英文）

基　　金：supported by MEXT Quantum Leap Flagship Program (MEXT Q-LEAP) Grant Number JPMXS0118067246。

摘　　要：For the practical use of femtosecond laser ablation, inputs of higher laser intensity are preferred to attain high-throughput material removal. However, the use of higher laser intensities for increasing ablation rates can have detrimental effects on ablation quality due to excess heat generation and air ionization. This paper employs ablation using BiBurst femtosecond laser pulses, which consist of multiple bursts(2 and 5 bursts) at a repetition rate of 64 MHz, each containing multiple intra-pulses(2–20 pulses) at an ultrafast repetition rate of 4.88 GHz, to overcome these conflicting conditions. Ablation of silicon substrates using the BiBurst mode with 5 burst pulses and 20 intra-pulses successfully prevents air breakdown at packet energies higher than the pulse energy inducing the air ionization by the conventional femtosecond laser pulse irradiation(single-pulse mode). As a result, ablation speed can be enhanced by a factor of23 without deteriorating the ablation quality compared to that by the single-pulse mode ablation under the conditions where the air ionization is avoided.

关 键 词：BiBurst mode GHz burst laser ablation SILICON air ionization 

分 类 号：TG665[金属学及工艺—金属切削加工及机床]