| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a method for producing an optical fiber preform derived to an optical fiber and having long constant-diameter part and thick diameter with a high yield. SOLUTION: This method for producing the optical fiber preform comprises forming a deposition 1 formed by depositing a glass particulate generated from a flame 11 of a burner 10 for core on the end of a starting glass rod 2 lifted while rotating to form a core deposited layer 6 and depositing the glass particulate generated from flames 13a and 13b of plural burners 12a and 12b for cladding arranged at higher position than the burner 10 for core on the periphery of the core deposited layer 6 to form a cladding deposited layer 5 and then sintering and is characterized by carrying out each the deposition at a constant position until the core deposited layer 6 becomes a desired length and stopping a supply of the raw material to the burner 10 for core and stopping the supply of the raw material to the burners 12a and 12b for cladding from the order at lower position while lifting the starting glass rod 2 to finish the formation of the deposition 1 after the core deposited layer 6 becomes the desired length.</p> |
