| 摘要 |
PURPOSE:To attain transmission of two signals in the same direction by transmitting two optical signals while one level of them is brought into a level being >=1.5 times the other and the signals are superimposed in one optical fiber, classifying the signals at three stages of threshold values at the reception side and inputting the result to a logical circuit. CONSTITUTION:The level of one signal 16 of the two optical signals to be transmitted is brought into a level being >=1.5 times the other level 17, the digital signals are synthesized at a half mirror and transmitted through the optical fiber while being superimposed. The signals are subjected to photoelectric conversion at a photodetector at the reception terminal as an electric signal 18 and the said electric signal is inputted to a comparator having three stages of threshold values 19-21 and processed by a logical circuit to decode the signal into two signals having the original levels 16, 17. Thus, the two optical signals are transmitted through the optical fiber with a simple device. |
