Damage Inside Borosilicate Glass by a Single Picosecond Laser Pulse

• Main Authors: Weibo Cheng, Jan-Willem Pieterse, Rongguang Liang
• Format: Article
• Language: English
• Published: MDPI AG 2021-05-01
• Series: Micromachines
• Subjects: laser-matter interaction; ultrashort pulse laser processing; plasma dynamics
• Online Access: https://www.mdpi.com/2072-666X/12/5/553

We investigate damage inside the bulk of borosilicate glass by a single shot of IR picosecond laser pulse both experimentally and numerically. In our experiments, bulk damage of borosilicate glass with aspect ratio of about 1:10 is generated. The shape and size of the damage site are shown to correspond to an electron cloud with density of about 10<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mn>20</mn></msup></semantics></math></inline-formula> cm<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msup><mrow></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></semantics></math></inline-formula>. The underlying mechanism of electron generation by multiphoton ionization and avalanche ionization is numerically investigated. The multiphoton ionization rate and avalanche ionization rate are determined by fitting experimental results. The relative role of multiphoton ionization and avalanche ionization are numerically studied and the percentage of electron contribution from each ionization channel is determined.