Study of Performance Improvement in Soliton Communication System
|關鍵字:||光固子;通訊系統;色散遞減光纖;四波混合;拖曳型濾波器;soliton;communication system;dispersion-exponentially-decreasing fiber;four-wave mixing;sliding filter|
In this dissertation, we propose different methods to improve the performance of optical soliton communication system. First, dispersion-exponentially-decreasing fiber is used as transmission fiber between amplifier spacing. Depletion of soliton energy by the four-wave mixing between soliton and amplifier noise in the system with large amplifier spacing is studied. The improvement of the system by the use of sliding-frequency filter to reduce noise power and the depletion of soliton energy is shown. The system can further be improved by compensating for depleted soliton energy. Second, the improvements of the Q factors of 10-Gb/s soliton systems detected by adjusting detection window are studied. We have found that the optimal width of the detection window depends on the noise-induced timing jitter, noise-induced soliton energy fluctuation, amplifier noise, dispersive wave, and soliton pulsewidth. Third, the method to stabilize dispersion-managed (DM) soliton in the presence of fiber loss and optical amplifiers is presented. We optimize in-line filter bandwidth and the relating excess gain for every amplification period so that the path average pulsewidth variation is minimized and the Q factors increases. Fourth, owing to the nature of frequency chirping of a dispersion-managed (DM) soliton, one can compress its pulsewidth with a dispersion compensation fiber at receiver so that the Q value of a DM soliton system can be improved. Numerical results show that significant improvement can be achieved with the pulse compression and proper time domain gating for filtering the radiated waves resulting from the pulse compression.
|Appears in Collections:||Thesis|
Files in This Item: