USE OF A YAG-ER LASER WITH A CHALCOGENIDE FIBER WAVE-GUIDE IN LASER-SURGERY

The damage thresholds of bulk high-purity chalcogenide glass samples a nd of fibre waveguides made from them were determined for YAG:Er laser radiation (lambda = 2.94 mu m). A cumulative effect was observed: the optical strength decreased during repetitive application of laser pul ses and this was true both of the bulk samples and of the fibre wavegu ides. A correlation between the damage threshold and the concentration of heterophase inclusions was established experimentally. When the in clusion concentration was less than 10(4) cm(-3), the damage threshold exceeded 1 kJ/cm(2) for single pulses and was approximately half that in the pulse-periodic regime. The measured energy density of the lamb da = 2.94 mu m radiation, needed for efficient cutting of the biotissu es of the crystalline lens of the human eye, amounted to 50 J/cm(2). T he feasibility of constructing a scalpel with an Er laser and transmis sion of its high-power radiation (up to 1 kJ/cm(2)) along a chalcogeni de fibre waveguide was demonstrated in principle.