| 摘要 |
PURPOSE:To minimize transmission loss by using polyoxymethylene to constitute a secondary covering layer formed on an optical fiber. CONSTITUTION:A primary covering layer 2 consisting of a silicone resin, UV curing type resin, etc., is provided on the outside circumference of the quartz optical fiber 1, by which the optical fiber 3 is formed; further, the secondary covering layer 4 consisting of the polyoxymethylene is provided on the outside circumference of this optical fiber 3, by which the optical fiber 5 is constituted. Namely, the polyoxymethylene (POM) is completely thermally decomposed in a relatively narrow temp. range of 230-320 deg.C and the secondary covering layer 4 is completely annihilated at 450 deg.C; therefore, there is no effect of accelerating the increase of the loss of the primary covering layer 2 which increases sharply from about 450 deg.C. The increase of the loss at the high temp. is thereby suppressed. |
