METHOD FOR MANUFACTURING POROUS GLASS PREFORM

摘要

PROBLEM TO BE SOLVED: To provide a method of manufacturing a porous glass preform which is capable of effectively eliminating the fluctuation (the fluctuation in the exter nal diameter) of the amount of glass particulate deposition in a turn-back posi tion of reciprocation motion and is low in the ratio of forming the non-effective section of an end in a high-speed multilayer deposition method of using a plural ity of burners and successively depositing the glass particulate synthesized by the burners on the surface of a starting rood while relatively moving the rotating starting rod and the burners back and forth. SOLUTION: The method of manufacturing the porous glass preform comprises performing the high-speed multilayer deposition method by a system of turning back the reciprocating motion after moving the burners by a distance±B around a reference point and setting the distance B at <1/2 the spacing L between the burners and changing the distance according to the growth of a glass particulate deposit.