PURPOSE: Sintering is carried out under specifically pressurized conditions to make it effective to contain volatile depants in the glass material, thereby glass for optical fiber is produced with well controlled distribution of dopant concentration.
CONSTITUTION: A starting material 10 for glass containing volatile dopants such as GeO2, Si3N4, F, e.g., glass fine particles, half-sintered glass or porous glass, is put in a vessel of high-purity quartz glass 11 and sealed under reduced pressure (about 1Torr). Then, the vessel 11 is put in the high-pressure sintering furnace 12 (13 means heaters) and a gas for pressurization such as argon is introduced into the furnace 12. Then, the vessel 11 is heated under pressure to effect sintering of the glass material 10 to give the objective glass for optical fiber. The glass vessel 11 itself can also be used as a clad for the optical fiber.
| JPS60231431 | MANUFACTURING APPARATUS OF OPTICAL POROUS GLASS BASE MATERIAL |
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HOSHIKAWA MASAO
TANAKA GOUTAROU
FUJIWARA KUNIO
SUMITOMO ELECTRIC INDUSTRIES