Dispersion-managed solitons at normal average dispersion

It has recently been shown that in strongly dispersion-managed fibers, consisting of a periodic dispersion map with alternating spans of anomalous and normal dispersion, solitons can exist not only with anomalous average dispersion, but also with zero and normal average dispersion. Here we find based on a reduced model that we have described elsewhere, that if the dispersion difference no between the anomalous and normal dispersion spans is higher than some threshold the dependence of the soliton energy S on the average dispersion D¯ is described by a C-shaped curve. Two different solitons of higher and lower energy and the same pulse duration can exist with normal average dispersion below a limiting value. We used a reduced model because it allowed us to rapidly explore a large parameter space, but we checked our results by full numerical simulations in key instances and found good agreement