Abstract
Based on the time when collisions govern the evolution of the phenomena, modeling of ultrafast laser-dielectrics interactions can be divided into three stages: 1) femtosecond pulse absorption through photon-electron interactions, including electron heating, excitation and generation; 2) electron-ion interactions, including energy transport, phase change and plasma generation; and 3) plasma expansion, shock wave propagation and radiation during plasma-environment interactions. This paper reports our ongoing efforts to investigate ablation threshold fluence, depth, and shape during femtosecond laser ablation of dielectrics through the Coulomb explosion and electrostatic ablation. A novel plasma model with quantum treatments is developed to account for significantly varying optical properties. The model is used to successfully predict two uncommon phenomena that were experimentally observed: 1) a flat-bottom crater shape created by a Gaussian beam and 2) repeatable nanoscale structures achieved by pulse train technology. By combining the plasma model and improved two-temperature model, 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.
Original language | English |
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Pages | 204-213 |
Number of pages | 10 |
Publication status | Published - 2008 |
Event | ICALEO 2008 - 27th International Congress on Applications of Lasers and Electro-Optics - Temecula, CA, United States Duration: 20 Oct 2008 → 23 Oct 2008 |
Conference
Conference | ICALEO 2008 - 27th International Congress on Applications of Lasers and Electro-Optics |
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Country/Territory | United States |
City | Temecula, CA |
Period | 20/10/08 → 23/10/08 |