| 摘要 |
PROBLEM TO BE SOLVED: To deal with plural bit rates, without having to detect each of bit rates. SOLUTION: An optoelectric converter 12 converts signal light inputted from an input terminal 10 to an electrical signal, and an amplifier 14 amplifies the output signal of the optoelectric converter 13. An LPF 16 removes a high-frequency noise from the output of the amplifier 14. A delay circuit 24 of a clock for extracting circuit 20 delays the output of the LPF 16 only for the time interval corresponding to the half cycle of a frequency which corresponds to the least common multiple(LCM) of plural bit rates. An exclusive OR circuit 22 exclusively ORs the output signal of the amplifier 14 and a signal, with which the output signal is delayed by the delay circuit 24. A narrow-band BPF 26 extracts frequency components corresponding to the LCM of bit rates of signal light to be identified/reproduced from the output of the exclusive OR circuit 22. According to the output of the BPF 26, an identification circuit 18 identifies, reproduces the output signal of the LPF 16 and outputs the corresponding binary electrical signal. An optoelectric converter 28 converts the output signal of the identification circuit 18 to an optical pulse signal. |
