Abstract
色散(Chromatic Dispersion)在單模光纖的高位元率信號傳輸中是一個會嚴重影響系統表現性能的問題，而導源於 Third-OrderSusceptibility 的光纖非線性亦是造成信號在傳輸過程中變形的一重要因素，為了避免由光纖色散效應造成的問題，使用操作波長在1.5 um 的色散位移光纖將很自然地是適當的選擇，而此兩效應都考慮進來後不管何者在 PSK(Phase-Shift-Keying) Coherent 解調系統中都會對訊號造成扭曲。The effects of both fiber dispersion and nonlinear -ity areconsidered in dealing with the optical wave propagation. Thevariation of the waveform of demodulated signal is found to beperiodic with re -spect to the total transmission distance.Andthe possibility of having such a periodic behavior is alsodependent on the bandwidth of the post detect -ion filter usedin the coherent receiver.