| 摘要 |
PURPOSE:To produce a functional rare earth element doped quartz glass fiber preform used for the optical fiber amplifier, etc. CONSTITUTION:The rare earth element-doped quartz glass rod used as the core of optical fiber is produced by flame-hydrolyzing a glass forming material and a dopant gaseous raw material for increasing the refractive index to form silica glass fine particles, depositing the silica particles to form a porous glass preform dipping the preform in a solution of a compound contg. the rare earth element, thereafter drying the preform and further sintering it at high temp. to convert it into transparent glass. Then, a glass forming gaseous raw material contg. a same kind of dopant gaseous raw material as the above dopant is subjected to flame hydrolysis to form silica glass fine particles. The silica fine particles are deposited to a prescribed thickness on the outer peripheral part of the quartz glass rod used as the core to form a hard glass layer to be used as the second core. Subsequently, silica glass fine particles formed by flame-hydrolyzing another glass forming gaseous raw material contg. no dopant is deposited on the hard glass layer to form a porous glass layer which is to constitute the clad or a part of the clad of the optical fiber. Thereafter, these are sintered to convert them into transparent glass layers. |
