Precise ablation of skin with reduced collateral damage using the femtosecond-pulsed, terawatt titanium-sapphire laser.

BACKGROUND AND DESIGN

The precise ablation of skin was studied using an ultrashort-pulsed, high-intensity titanium-sapphire (Ti:Al2O3) laser capable of peak intensities of tens of terawatts (TW; 1 TW = 10(12) watts [W]) per square centimeter. Rat skin was exposed in vitro to femtosecond-pulsed Ti:Al2O3 laser radiation at 800 nm, while varying the number of pulses and the intensity up to 46 TW/cm2. Ablation was evaluated by monitoring the amount of tissue removed per pulse as a function of energy, and by light microscopic examination of damage to adjacent, nonirradiated tissue.

OBSERVATIONS

Ablation depth per pulse was 0.1 micron at threshold intensity, and it was increased with both the energy per pulse and the number of pulses. Minimal damage to adjacent healthy tissue was observed, varying 0 to 30 microns.

CONCLUSION

The results suggest that ablation of skin with femtosecond-pulsed, terawatt Ti:Al2O3 laser may have potential for precision cutaneous surgery, and in vivo studies are indicated.