| 摘要 |
PURPOSE:To attain always supervision of an optical transmission line only by using an optoelectric converting section to receive a light from an electrooptic conversion section and a light circulated through an optical loop transmission line and comparing the both so as to supervise the optical loop transmission line. CONSTITUTION:In supervising the loop optical transmission line 2, rays of light transmitting filters 7a-7d are irradiated from the electrooptic conversion section 8 in an opposite direction to the right rotary signal transmission loop shown in the arrow in the transmission line 2, the rays of light are reflected in a half mirror 5a and received by the optoelectric converting section 9 via the filter 7a and a half mirror 6a, and the rays of light circulated in opposite direction in the signal transmission loop of the line 2 from the rays of light transmitting through the half mirror 6a are reflected and received by the optoelectric converting section 9, and the both are compared to attain supervision. Thus, only the optical transmission line of the optical transmission system is supervised always. |
