Temperature and shock wave propagation in water (as a model of tissue) irradiated by sub-picosecond and nanosecond pulses were modeled. The high temperature and pressure generated during sub-picosecond irradiation did not penetrate deeply into the water due to quickly ejected plasma while significant pressure and temperature increases were observed in deep regions with nanosecond pulses. Knowing that the sub- picosecond pulses are effective for tissue ablation, additional studies were done to examine the effect of short pulse widths (less than 20 ps). Ablation threshold, temperature rise and ablation crater quality on human dentine were investigated for different pulse widths in the range of 150 fs - 20 ps. The ablation threshold fluence was approximately 4 times higher with 20 ps pulses than with 150 fs pulses but the quality of the alation craters were not significantly different in this pulse width range.

Date Published: 13 May 1998
PDF: 8 pages
Proc. SPIE 3254, Laser-Tissue Interaction IX, (13 May 1998); doi: 10.1117/12.308165

Published in SPIE Proceedings Vol. 3254:
Laser-Tissue Interaction IX
Steven L. Jacques; Jeff Lotz, Editor(s)