Temperature distribution of preform in drawing silicon core optical fiber with CO₂ laser heating

This paper presents a physical model about the temperature distribution of a silicon preform exposed to a 10.6 m CO2 laser in consideration of air convection and environmental radiation heat transfer. In the meantime, an approach of heating the preform by the laser combining with graphite furnace is suggested. Simulation results show that the temperature distribution is strongly dependent on the parameters of the CO2 laser and the preform, and laser heating is appropriate for preform with diameter less than 10 mm when the laser spot radius is 3 mm and laser power is 400 W. Heating combining with graphite furnace can modulate the temperature gradient effectively and build the correct temperature field for silicon core fiber drawing.