Abstract

Long-distance signal transmission, made possible with in-line optical amplifiers [1], suffers from nonlinear phenomena arising in optical fibers. A transmitted signal very near the zero- dispersion wavelength undergoes a remarkable noise increase due to four-wave mixing (FWM) between the signal and the amplified spontaneous emission (ASE) [2]. On the other hand, when the signal wavelength is further away from the zero-dispersion wavelength, the combined effect of self-phase modulation (SPM) and group-velocity dispersion (GVD) causes waveform distortion and limits the allowable transmission distance. Although compensation of GVD is effective in alleviating this limitation [3],[4], no quantitative discussion has been carried out. In this paper, GVD compensation in in-line amplifier systems is evaluated by numerically solving the nonlinear Shrodinger equation (NLSE). Improvement in transmission distance and the optimum amount of dispersion compensation are clarified.

© 1993 Optical Society of America