PRODUCTION OF FIBER BASE MATERIAL FOR LIGHT COMMUNICATION

摘要

PURPOSE:To produce a porous preform by setting a jacket burner over a clad burner in close vicinity to it; separately attaching a core-clad exhaust pipe and a jacket exhaust pipe; and treating finely divided glass raw materials by a vapor phase axially adhering method to prevent the raw materials from mixing. CONSTITUTION:A jacket burner 14 is set over a clad burner 12 of four-layer structure in close vicinity to the burner 12 so that the flames of the burners are continuously formed. Thus, jacket glass fine powder can be grown on clad glass fine powder before the surface temp. of the clad glass fine powder lowers slightly, thereby producing a porous preform with little difference in bulk density. In the vicinity of growing surface 160 of core glass fine powder and growing surface 162 of clad glass fine powder, core-clad exhaust pipe 18 with one end open is set. In the vicinity of growing surface 164 of jacket glass fine powder, jacket exhaust pipe 20 with one end open is separately set.