| 摘要 |
PURPOSE:To test and monitor each of a pair of optical fibers for two-way transmission with a small device by selectively switching the test light fed from a light pulse tester with a light switching circuit. CONSTITUTION:A light transmission line 8-1 sends the signal light from a transmitter 1 to an optical fiber 5-1. A light transmission line 8-2 sends the arriving signal light lambda, to a receiver 2 via an optical fiber 5-2. The test light lambda2 transmitted from a pulse tester 3 is guided to a light switching circuit 13 via a light transmission line 8-5 and selectively switched, and it is sent to a light transmission line 8-3 or 8-4 and the transmission line 8-1 or 8-2 via a merging/diverging unit 6-1 or 6-2. The light lambda2 enters the fiber 5-1 or 5-2 and is propagated, it is reflected by a demarcating unit provided near the mating terminal, then it retrogresses on the line and is returned to the tester 3. When the reflected light quantity value is monitored, the deterioration of the transmission characteristic of the fiber 5-1 or 5-2 can be evaluated. |
