Abstract
The interaction of a 200-µs Er:YAG laser at 2.94 µm with human molar dentine has been studied by ablation depth rate measurements as well as time-resolved and optical multichannel analyzer emission spectroscopy. Ablation rates indicate a threshold fluence of ~5.2 J cm−2 for significant material removal with a low-fluence (<20 J cm−2) effective optical absorption coefficient of ~700 cm−1. Deviation from a Beer’s law dependence is significant in the range ~20 to ~60 J cm−2 and indicates a maximum effective plume absorption of ~1200 cm−1 at ~40 J cm−2, coinciding with the appearance of strong line and broadband optical emission in the visible region. Time-of-flight emission measurements yield maximum species-resolved ablation velocities of up to ~1.2 × 106 cm s−1, enabling calculation of plasma temperatures. The results suggest that etch-rate characteristics are driven by changes in plume absorption dynamics, which have a strong dependency on incident laser fluence.
© 1997 Optical Society of America
Full Article | PDF ArticleMore Like This
Lina M. Beltrán Bernal, Ferda Canbaz, Antoine Droneau, Niklaus F. Friederich, Philippe C. Cattin, and Azhar Zam
Biomed. Opt. Express 11(12) 7253-7272 (2020)
T. G. Barton, H.-J. Foth, M. Christ, and K. Hörmann
Appl. Opt. 36(1) 32-43 (1997)
Zahraa J. Naeem, Ansam M. Salman, Rawaa A. Faris, and Abdulhadi Al-Janabi
Appl. Opt. 60(21) 6189-6198 (2021)