| 摘要 |
PURPOSE:To efficiently produce a preform for optical fibers without wasting an available part of a starting material, by forming a deposit of fine glass particles on the outer peripheral part of the available part of the starting material so that the outside diameter may be constant in the longitudinal direction. CONSTITUTION:A burner for synthesizing fine glass particles (the figure thereof is omitted) is moved parallel relatively to the axis of a starting material consisting of a nonavailable part 1, e.g. dummy rod, etc., and a high-purity available part 2 usable as a glass body for optical fibers to form a deposit 3 of the fine glass particles on the outer peripheral part of the starting material. In the above-mentioned method, the deposition of the fine glass particles is started from the nonavailable part 1 in the upper part of the starting material. Furthermore, the deposition of the fine glass particles is completed after the outside diameter of the deposit 3 thereof in the outer peripheral part at the lower end of the above-mentioned available part 2 attains a stationary state. Thereby the deposit 3 of the fine glass particles having a constant outside diameter in the longitudinal direction thereof is formed on the outer peripheral part of the above-mentioned available part 2. |
