Thermal and optical modeling of 'blackened' tips for diode laser surgery

摘要

This paper presents the results of thermal and optical modeling of "blackened" tips (fiber-optic thermal converter) with different structures: film and volumetric. Film converter is created by laser radiation action on a cork or paper and it is a one-step process. As a result, a carbonized cork or paper adhered to the distal end of the optical fiber absorbs light that leads to heating of the distal end of the optical fiber. We considered the peculiarities of volumetric converters formed by sintering (second step) of the target material transferred to the tip, at irradiating the target with laser radiation (first step). We investigated the interaction between 980 nm laser radiation and converters in the air and water. As a result of experiments and modeling, it was obtain, that converter temperature and power of converter destruction depend on the environment in which it is placed. We found that film converter in the air at average power of laser radiation of 0.30±0.05 W is heated to 900±50°С and destructed, and volumetric converter in the air at average power of laser radiation of 1.0±0.1 W is heated to 1000±50°С and destructed at reaching of 4.0±0.1 W only. We found that film converter in the water at average power of laser radiation of 1.0±0.1 W is heated to 550±50°С and destructed at reaching of 4.0±0.1 W only. Volumetric converter at average power of laser radiation of4.0±0.1 W is heated to 450±50°С and is not destructed up to 7.5±0.1 W, it is heated to 500±50°С in this case. Thus, volumetric converter is more resistant to action of laser heating.