| 摘要 |
PURPOSE:To provide a high-productivity preparation of optical transmission line having dense sectional area and desired refractive index distribution by a method wherein a glass tube internal surface is formed with layer whose optical property is different from the glass tube, heated to form into a rod, then is spinned into fiber form. CONSTITUTION:The internal surface of a transparent glass material tube 5 is smoothed, on which a glassy deposited layer 6 whose optical property is different from the glass tube 5 is formed. This complex body is charged in a furnace 7 and is heated to about its melting temperature so that the center hollow section is closed to form into a rod. The formed rod has the deposited layer 6 whose density is higher than that of the outer glass. The rod is inserted into a second tube whose media 8, 9 have desired refractive index. This combination glass is heated in the furnace 7 and is spinned to form a fiber. The fiber, as required, undergoes heat treatment to enhance light transmissin. |
