QUASI-STABLE SOLITON TRANSMISSION IN A LONG-DISTANCE FIBER LINK WITH PERIODIC DISPERSION MANAGEMENT AND LUMPED AMPLIFIERS

Nonlinear pulse propagation in a fibre link with periodic dispersion m anagement (DM) is investigated, taking into consideration the effect o f fibre loss. The mechanism that the quasi-stable soliton can exist in a dispersion-managed fibre is revealed. It is found that in the lossl ess case more energy is required for forming a quasi-stable soliton th an the regular soliton in a uniform fibre system. However, when fibre loss is included, and for sufficiently large amplifier spacing, the re quired soliton energy in the dispersion-managed system is found to app roach the same value as in a uniform fibre system, and thus the potent ial advantage of increased soliton energy in a DM fibre link is dimini shed with fibre loss. The shape of such a quasi-stable soliton is a ne arly hyperbolic secant with loss but more Gaussian-like without loss.