ablation of biological tissue

This paper presents a comprehensive review of the CO2 laser ablation of biological tissue. Based on energy balance for modelling laser ablation, the thermal relaxation time and the ablation threshold are determined. Laser ablation of biological tissue is related to the spatial coherence of laser beams, so that the propagation of laser beams, the beam quality and the focusability of laser beams are taken into consideration. To achieve the ablation threshold, the laser irradiance in the focal zone is computed as a function of laser parameters. The advantages of pulsed operation of the CO2 laser for minimum residual thermal damage of the tissue are stressed. The strengths and the weaknesses of the CO2 laser ablation are fmally discussed.