| 摘要 |
PURPOSE:To fit a conducting wire securely without requiring high-level special technique and to detect a flaw, etc., in an optical fiber by sheathing an optical fiber with a heat-shrinkable resin tube where a low-fusion-point conductor and a conducting wire which constitute a fractive detecting circuit for the optical fiber are fitted. CONSTITUTION:An insulating jacket layer 7 is formed on the outer circumferential surface of the optical fiber and the conductor D is provided along the surface. The core part 4 of the conducting wire R is superposed in the lengthwise direction of the conductor D, and the heat-shrinkable resin tube 8 is fitted externally covering the fitting position and shrunk thermally to fit each conducting wire R in press contact with each conductor D. If laser light leaks owing to a flaw, breaking, etc., of the optical fiber F, the conductor D is fused by its heat operation and broken and signal currents suplied from conducting wires R fitted at both sides of the broken conductor D are cut off, so the fracture of the optical F is detected. |
