| 摘要 |
Disparities in reception strength, which arise from the strength difference and optical path difference of an optical signal in an optical receiver adapted to an RZ-DPSK modulation system, cannot be automatically corrected. Therefor, an optical receiver is disclosed that is provided with a first photodiode that receives a normal phase optical signal from the first output terminal of a 1-bit delay interferometer and outputs a positive signal, a second photodiode that receives a reversed phase optical signal from the second output terminal of the 1-bit delay interferometer and outputs a complementary signal, a differential transimpedance amplifier that inputs the positive signal and the complementary signal and is provided with respective closed feedback loops for the input of the positive signal and the complementary signal, a level adjustment unit that adjusts the signal level in the closed feedback loops, and a photoelectric current detection unit that detects the respective photoelectric currents generated by the first photodiode and the second photodiode; and the level adjustment unit adjusts the signal levels on the basis of the output of the photoelectric current detection unit. |
