发明名称 |
METHOD FOR PRODUCING A GLASS OPTICAL FIBER PREFORM |
摘要 |
There is provided a method for producing an optical fiber preform used in producing an optical fiber having low attenuation. The production method includes (1) a rod formation step of forming a glass rod of a silica glass containing an alkali metal element, the average concentration of the alkali metal element being 5 at.ppm or more, (2) a heat treatment step of heat-treating the glass rod, (3) a core part formation step of forming an alkali metal element-free silica glass layer having a chlorine concentration of 6000 at.ppm or more around the perimeter of the glass rod heat-treated in the heat treatment step to form a core part including the glass rod and the silica glass layer, and (4) a cladding part formation step of forming a cladding part of a silica-based glass having a lower refractive index than the core part around the perimeter of the core part. |
申请公布号 |
EP2722317(B1) |
申请公布日期 |
2017.03.01 |
申请号 |
EP20140150752 |
申请日期 |
2012.01.26 |
申请人 |
Sumitomo Electric Industries, Ltd. |
发明人 |
Haruna, Tetsuya;Hirano, Masaaki;Tamura, Yoshiaki |
分类号 |
C03B37/012;C03B37/014;C03B37/018;C03C13/04 |
主分类号 |
C03B37/012 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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