PRODUCTION OF OPTICAL FIBER BASE MATERIAL

摘要

PURPOSE:To easily obtain the optical fiber base material which is less changed in the density in the diametral direction by decreasing the intensity of the DC electric field for accelerating the fine particles of the resulted product of a hydrolysis with an increase in the outside diameter of the base material at the time of producing the optical fiber base material by sticking the fine particles thereto. CONSTITUTION:The gaseous raw materials (for example, SiCl4, GeCl4) blown out of an oxyhydrogen burner 2 are hydrolyzed in an oxyhydrogen flame 9 to synthesize the fine particles 7. The fine particles 7 are stuck to a target, by which the porous optical fiber base material 8 is produced. Speed of the above-mentioned fine particles is accelerated by the DC electric field generated by impressing a DC voltage to an electrode 3 disposed within the above- mentioned burner 2 at this time. The intensity of the above-mentioned DC electric field is decreased with an increase in the outside diameter of the above- mentioned target, by which the sticking speed of the fine particles is suppressed. The change in the density in the diametral direction of the optical fiber base material 8 is thus suppressed and the optical fiber base material which is less changed in the density of the diametral direction is easily obtd.