Abstract

The performance of soliton communication systems transmitting high data rates over large distances is dominated by the effects of amplified spontaneous emission ASE arising from the erbium-doped fibre amplifiers necessary to sustain the soliton energy in the presence of fibre attenuation. Previous analysis of this effect [1,2] has concentrated on the behaviour of a single soliton in the presence of cumulative amplifier noise; the classic analysis of Gordon-Haus [1] demonstrated that RMS position jitter of about 1 soliton FWHM occurred at a propagation distance of 2300 km in a system in which the soliton FWHM was 10 ps, the soliton length scale was 8 km and the amplifier gain was 1.26. This permits a BER of 10^-9 if the interpulse period is 100 ps, corresponding to a bit rate of 10 Gb s⁻¹. A critical assumption in this type of calculation is that the interpulse spacing T is large enough to neglect any interactions between solitons. The present author has shown that if x << L, where x is the normalised propagation distance and L is the stability length defined by L = (1/4)exp(T/2), then a periodic pulse train of period T behaves essentially as isolated solitons; in the Gordon-Haus calculations [1] x/L= 0.14.

© 1993 Optical Society of America