| 摘要 |
PURPOSE:To obtain a communication network constituted with cheap and stable terminal accessories, by consituting the accessory of the connection part between each terminal and the optical fiber by a spectroscope having wave length selectivity and by assigning one of different wave length to each terminal. CONSTITUTION:Light waves of wave length lambda1, lambda2 and lambda3 are assigned to terminals 110-130 respectively, and three light waves are propagated through ring light transmission line 10 clockwise. In terminal accessory 51 of terminal 110, only the light wave of wave length lambda1 is input to terminal control unit 61, and light waves of other wave length are propagated through light transmission line 10 as they are. The signal from terminal 110 to center 50 is carried by the light wave of wave length lambda1 from unit 61 and is transmitted through accessory 51 in transmission line 10. Accessories are constituted by optical fibers 10' and 10'' for transmission line, optical fibers 111 and 112 for terminal, lenses 113-116, and dielectric multilayer film filters 117 and 118, and filters cause only the light wave of one wave length to pass through and reflects light waves of other wave length. |
