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) lase r 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 fem tosecond-pulsed Ti:Al2O3 laser radiation at 800 nm, while varying the number of pulses and the intensity up to 46 TW/cm2. Ablation was evalu ated by monitoring the amount of tissue removed per pulse as a functio n of energy, and by light microscopic examination of damage to adjacen t, nonirradiated tissue. Observations: Ablation depth per pulse was 0. 1 mum at threshold intensity, and it was increased with both the energ y per pulse and the number of pulses. Minimal damage to adjacent healt hy tissue was observed, varying 0 to 30 mum. Conclusion: The results s uggest that ablation of skin with femtosecond-pulsed, terawatt Ti:Al2O 3 laser may have potential for precision cutaneous surgery, and in viv o studies are indicated.