METHOD FOR PRODUCING PREFORM FOR OPTICAL FIBER USING MCVD METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for producing a glass preform in high yield and free from occurrence of outer diameter fluctuation, fracture or the like by forming thicker glass layer than in conventional process with respect to MCVD (modified chemical vapor deposition) method. SOLUTION: This method for producing an optical fiber preform by MCVD method comprises the steps of traversing a heating burner once or several times to pile up glass layer inside a glass pipe while flowing glass raw material containing gas inside the glass pipe as inside deposition step, and then removing soot piled up on the downstream side from the traverse turning part by physical scraping and/or chemical process (vapor phase etching) where the removing operation as being one set is carried out once or several times of sets.