发明名称 |
Preform with a barrier layer against hydrogen diffusion in an optical fibre started from the preform and preparation process of this preform |
摘要 |
<p>Optical fiber preform, has an external alumina-doped silica cladding (28) with a peripheral zone (25) of 0.08-2.2 R thicknes and of alumina content providing a relatively low equivalent alumina concentration throughout the external cladding. Silica-based optical fiber preform comprises a core (20) of radius (R), an internal optical cladding (21) in direct contact with the core and an external cladding (28) of alumina-doped silica. The novelty is that (a) the external cladding has an internal zo (27) in direct contact with the optical cladding and a peripheral zone (25) which is in direct contact with the internal zone an which consists mainly of alumina-doped silica; (b) the peripheral zone (25) has a thickness of 0.08-2.2 R; and (c) the quantity alumina in the peripheral zone is such that the equivalent concentration of alumina throughout the external cladding corresponds 100-1000 ppm aluminum by wt. of the silica. Independent claims are also included for: (1) a process for production of the above preform; and (2) an optical fiber manufactured from the above preform or a preform made by the above process</p> |
申请公布号 |
EP1048623(A1) |
申请公布日期 |
2000.11.02 |
申请号 |
EP20000401136 |
申请日期 |
2000.04.25 |
申请人 |
ALCATEL |
发明人 |
ORCEL, GERARD;DUBOIS, SOPHIE;CAMPION, JEAN-FLORENT |
分类号 |
G02B6/00;C03B37/012;C03B37/014;C03B37/018;C03C13/04;G02B6/02;G02B6/036;G02B6/44;(IPC1-7):C03B37/012;G02B6/16 |
主分类号 |
G02B6/00 |
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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