Parametric Trapping and Self-Ordering of Solitons

One basic problem in high bit rate soliton communication and storage systems is the soliton’s time position jittering. This jittering is caused by the soliton frequency diffusion which originates either from amplified spontaneous emission in repeaters [1] or from soliton-soliton interactions. Use of filtering along with amplification in repeaters permits only partially suppress the time position jittering [2,3]. Without filtering mean-square time position increases as distance cubed, whereas with filtering it increases linearly in distance. Recently big progress was achieved in experiment of M.Nakazawa with the help of active modulation of losses along with filtering and amplification of solitons [4]. Modulator provides a clocking mechanism by which an ordering of solitons occurs, whereby each of solitons tends to occupy a time interval when the modulator has a maximum transmission. However, in practical use of this method for a communication line, when a number of modulators is needed, a serious problem of mutual synchronization of all those modulators arises. In addition, the bit rate is limited by the modulator electronics. The way-out is a passive mechanism of ordering or a mechanism of self-ordering of solitons which does not require electronics.