Title: Micro drilling of PMMA with double-pulse femtosecond laser

Authors: Jiaqun Li; Hongfei Shang; Jianfeng Yan; Ming Qiao; Jiachen Yu; Dezhi Zhu; Chao He

Addresses: State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China ' State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China ' State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China ' State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China ' State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China ' State Key Laboratory of Tribology, Department of Mechanical Engineering, Tsinghua University, Beijing 100084, China ' ACUNITY GmbH, Steinbachstr, 15, Aachen, 52074, Germany; Fraunhofer Instutite for Laser Technology ILT, Steinbachstr. 15, Aachen, 52074, Germany

Abstract: Micro holes drilling in polymers have a variety of applications in industry and research. Especially, the fabrication of micro hole with high aspect ratio is a key technology for advanced applications. In this work, we report an improvement in drilling on poly-methyl methacrylate (PMMA) by using double-pulse femtosecond laser. Compared to single pulse, the achievable depth by double pulses can be increased by 50% when the pulse delay is 100 fs and gradually decreases with delay increasing. The depth evolution with the increasing of pulse number is investigated. When the micro hole depth reaches a certain value, the processing speed of double pulse is less restricted than single pulse. Furthermore, the relationship between the depth improvement and electrons decay together with absorption increase is studied.

Keywords: micro holes drilling; polymers; femtosecond laser; double pulses; high aspect ratio.

DOI: 10.1504/IJHM.2023.129122

International Journal of Hydromechatronics, 2023 Vol.6 No.1, pp.34 - 44

Received: 14 Mar 2022
Accepted: 29 Apr 2022
Published online: 21 Feb 2023 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article