PRODUCTION OF INFRARED RAY FIBER

摘要

PURPOSE:To enable production of infrared fibers of reduced transmission loss with formation and growth of crystal grains inhibited, by effecting melt spinning as the area near the nozzle is locally heated at the bottom of the crucible to keep the viscosity of the glass melt in a specific range. CONSTITUTION:Chalcogenide glass 1 is charged in a crucible 2 and fitted to a heating furnace 3 which can heat the bottom end of the crucible in 8mm width. The crucible is locally heated near the spinning nozzle to soften the glass 1 to maintain the viscosity of the melt in the range from 10<5>-10<7> poise. The crucible is pressurized from the top with using argon gas and an infrared glass fiber 5 is pulled out of the nozzle. Immediately after spinning, the fiber 5 is rapidly cooled down. Thus, the formation and growth of crystal grains can be suppressed at a low level and continuous infrared fiber 5 of low transmission loss is stably produced.