We present a theoretical model for laser cutting of biological tissue by a strongly heated fiber tip with a highly absorbing coating. A significant dependence of the cutting speed and cutting depth on the inclination angle of the scalpel to the surface when scattering exceeds absorption in the biological tissue is shown. Experimental evidences of this effect are presented. In the experiment, we used silica fiber with coating made of carbon and silicon organic varnish, the 0.97-µm wavelength laser and porcine skin. The additional opportunity to increase the efficiency of cutting by deposition of the absorbing layer on the tissue surface is considered.
Keywords: (140.6810) Thermal effects; (170.0170) Medical optics and biotechnology; (170.1020) Ablation of tissue.