| 摘要 |
PURPOSE:To simplify the constitution of a line monitor when there is a difference in sensitivity with which light is received between forward light and reverse light. CONSTITUTION:A line monitor has an incidence fiber 1 and an outgoing fiber 2 for signal light, a half mirror 5 for reflecting part of forward light incident from the incidence fiber and part of reverse light incident from the outgoing fiber, and light receiving elements 6, 7 for receiving the forward light and the reverse light, respectively, both of which light are reflected at the half mirror. Since the half mirror 5 is inserted in the divergent beam of the forward light, the forward light reflected is incident on the light receiving element 6 with a large spot size and the reverse light reflected is incident on the light receiving element 7 with a small spot size. |
