| 摘要 |
<P>PROBLEM TO BE SOLVED: To make it hard to receive the wave distortion due tp nonlinear optical effects and wavelength dispersion by narrowing the occupied band of a channel. <P>SOLUTION: An optical duobinary signal generating circuit 101 generates an optical duobinary signal which has an optical occupation band narrower than an NRZ signal. An optical gate circuit 111 generates a D-RZ signal by returning the above optical duobinary signal to zero. An optional filter 121 suppresses the harmonic components of the D-RD signal. That is, the optical filter 121 passes the center peak and the peaks on both sides. In short, the transmission band of the light filter 121 becomes triple the transmission rate. What is more, if the passband of the optical filter 121 becomes B, the output becomes NRZ, and not RZ. <P>COPYRIGHT: (C)2004,JPO |
