| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical transmission system without the need for using a band-pass filter and a PLL circuit to extract a received clock and not vulnerable to the effect of a transmitted signal pattern. <P>SOLUTION: In the optical transmission system 10, a transmission side 1 includes a laser drive circuit 11 operated by a data signal and a clock signal and a laser diode 12, transmits an optical signal to a reception side 2 through an optical fiber cable 13, and the reception side 2 recovers the data signal and the clock signal. The transmission side 1 superimposes an 'H' level of the clock signal on a '0' level of the data signal and also superimposes an 'L' level of the clock signal and a DC bias on a '1' level of the data signal. A clock extraction circuit 19 comprising differential amplifiers 44, 47, limiter amplifiers 45, 48, and an OR gate 49 in the reception side 2 extracts the clock signal on the basis of the received signal and detected outputs by a data 'H' level detection circuit 17 and a data 'L' peak detection circuit 18. <P>COPYRIGHT: (C)2004,JPO |
