A plasma model combined with an improved two-temperature equation for ultrafast laser ablation of dielectrics

Journal Article · Sat Nov 01 04:00:00 EDT 2008 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3006129· OSTI ID:21185883

Lan, Jiang ^[1]; Tsai, H -L ^[2]

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1. Laser Micro-/Nano-Fabrication Laboratory, Department of Mechanical and Automation Engineering, 3rd School, Beijing Institute of Technology, Beijing 100081 (China) and Laser-Based Manufacturing Laboratory, Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology Rolla, Missouri 65409 (United States)
2. Laser-Based Manufacturing Laboratory, Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology Rolla, Missouri 65409 (United States)

It remains a big challenge to theoretically predict the material removal mechanism in femtosecond laser ablation. To bypass this unresolved problem, many calculations of femtosecond laser ablation of nonmetals have been based on the free electron density distribution without the actual consideration of the phase change mechanism. However, this widely used key assumption needs further theoretical and experimental confirmation. By combining the plasma model and improved two-temperature model developed by the authors, this study focuses on investigating ablation threshold fluence, depth, and shape during femtosecond laser ablation of dielectrics through nonthermal processes (the Coulomb explosion and electrostatic ablation). The predicted ablation depths and shapes in fused silica, by using (1) the plasma model only and (2) the plasma model plus the two-temperature equation, are both in agreement with published experimental data. The widely used assumptions for threshold fluence, ablation depth, and shape in the plasma model based on free electron density are validated by the comparison study and experimental data.

• OSTI ID: 21185883
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 9 Vol. 104; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABLATION
DIELECTRIC MATERIALS
ELECTRON DENSITY
EQUATIONS
EXPLOSIONS
IONIZATION
LASERS
LIGHT TRANSMISSION
NONMETALS
PLASMA
PLASMA DENSITY
SILICA