@article{d80c0850bfd6484d8ea28cf54c09c190,
title = "Deep-hole drilling of amorphous silica glass by extreme ultraviolet femtosecond pulses",
abstract = "A free-electron laser (FEL) is a robust tool for studying the interaction of intense X-rays with matter. In this study, we investigate the damage threshold and morphology of fused silica irradiated by extreme ultraviolet femtosecond pulses of a FEL. The experimental results indicate the superiority of the FEL processing. The FEL-damage threshold of fused silica at a wavelength of 13.5 nm is 0.17 J/cm2, which is 20 times lower than that of a near infrared (NIR) femtosecond laser. The relationship between the crater depth and laser fluence reveals that the effective absorption length is αeff -1 = 58 nm. The damage threshold and the absorption length are the key values for smooth crater formation. In addition, the formation of rim structures and microcracks, which are usually the critical issues in NIR laser processing, cannot be found in the interaction region. The hole diameter is maintained below the beam size at the exit.",
author = "Tatsunori Shibuya and Takashi Takahashi and Kazuyuki Sakaue and Dinh, {Thanh Hung} and Hiroyuki Hara and Takeshi Higashiguchi and Masahiko Ishino and Yuya Koshiba and Masaharu Nishikino and Hiroshi Ogawa and Masahito Tanaka and Masakazu Washio and Yohei Kobayashi and Ryunosuke Kuroda",
note = "Funding Information: This work is based on results obtained from the New Energy and Industrial Technology Development Organization (NEDO) project “Development of advanced laser processing with intelligence based on high-brightness and high-efficiency laser technologies (TACMI project).” The XFEL experiments were performed at BL1 in SACLA with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal Nos. 2017B8004 and 2018A8024). A part of this work was conducted at the AIST Nano-Processing Facility (AIST-NPF), supported by the “Nanotechnology Platform Program” of the Ministry of Education, Culture, Sports, Science and Technology (MEXT), Japan. The authors would like to thank Mr. Masanori Iitake for operating the FIB machine at the AIST-NPF and Dr. Kon (JASRI) and Dr. Owada for their support in the experiments at SACLA BL1. Publisher Copyright: {\textcopyright} 2018 Author(s).",
year = "2018",
month = oct,
day = "8",
doi = "10.1063/1.5046125",
language = "English",
volume = "113",
journal = "Applied Physics Letters",
issn = "0003-6951",
publisher = "American Institute of Physics Publising LLC",
number = "15",
}