Abstract
Because of the unique properties with regard to the absorption in organic tissue, pulsed Er:YAG laser has found most
interest for various application in medicine, such as dermatology, dentistry, and cosmetic surgery. However, consensus
regarding the optimal parameters for clinical use of this tool has not been reached. In this paper, the laser ablation
characteristics of soft tissue by Er:YAG laser irradiation was studied. Porcine skin tissue in vitro was used in the
experiment. Laser fluences ranged from 25mJ/mm2 to 200mJ/mm2, repetition rates was 5Hz, spot sizes on the tissue surface was 2mm. The ablation effects were assessed by the means of optical microscope, ablation diameters and depths
were measured with reading microscope. It was shown that the ablation of soft biotissue by pulsed Er:YAG laser was a
threshold process. With appropriate choice of irradiation parameters, high quality ablation with clean, sharp cuts
following closely the spatial contour of the incident beam can be achieved. The curves of ablation crater diameter and
depth versus laser fluence were obtained, then the ablation threshold and ablation yield were calculated subsequently, and the influence of the number of pulses fired into a crater on ablation crater depth was also discussed.
