| 摘要 |
PURPOSE:To improve the minimum strength of an optical fiber and improve the reliability for a long term, by forming a glass layer having a larger refractive index and a lower thermal expansion coefficient than a cladding glass on the surface of the optical fiber. CONSTITUTION:A glass layer is made from a SiO2-TiO2 glass system. Fine glass particles of SiO2, GeO2, etc. are deposited respectively on the end of a lifting and rotating starting material by a burner 21 to form a core porous glass material 27. Fine glass particles of SiO2 are then deposited on the surface of the core porous glass material 27 by a burner 22 to form a cladding porous glass material 28. Fine glass particles of SiO2 and TiO2 are further deposited on the surface of the cladding porous glass material 28 by a burner 23 to form a porous glass material 29. The resultant porous glass material 29 is then deaerated in an electric furnace heated at about 1,500 deg.C to give a transparent base material for an optical fiber. |
