摘要 |
<p>Provided is an optical transmission line (60) that allows optical signals to be transmitted with higher stability over longer distances. According to a first aspect of the invention, an optical NRZ signal is split in two, one half is presented to a clock extraction circuit (3), and the other half is presented to an EA modulator (5). An optical RZ signal is obtained as an output because the EA modulator is energized by the clock component provided. According to a second aspect of the invention, a nonlinear phase shift based on cross-phase modulation is induced in an RZ pulse train by an optical NRZ signal, and only the RZ pulses corresponding to the optical NRZ signal are extracted. According to a third aspect of the invention, first dispersion compensation means (61) are provided to a preceding stage of an optical fiber transmission line for transmitting optical pulses, and second dispersion compensation means (63) are provided to a subsequent stage. Pulse widening in the optical fiber transmission line is controlled by a nonlinear chirp induced in the first dispersion compensation means. <IMAGE></p> |