| 摘要 |
PROBLEM TO BE SOLVED: To allow more improved light receiving sensitivity to contribute to realization of non relay transmission. SOLUTION: The receiver is provided with an optical amplifier 101 amplifying an optical signal from an optical transmission line, a 1st photoelectric converter 104 applying photoelectric conversion to an output of the optical amplifier 101 and an identification device 105 to identify a transmission signal from an output of the 1st photoelectric converter 104. In this case, an electric field absorption type modulator 102 whose transmission rata is high when a level of an input optical signal is high and whose transmission rate is low when the level of the input optical signal is low is interposed between the optical amplifier 101 and the 1st photoelectric converter 104. The electric field absorption type modulator 102 improves the extinction ratio of the input signal light by utilizing the change in the transmission rate depending on the input optical intensity and suppresses optical noise at transmission of space simultaneously and the light receiving sensitivity is rapidly improved. |
