INTERACTIONS IN BRIGHT N-SOLITON TRAINS PROPAGATING IN BIREFRINGENT OPTICAL FIBERS

The role of birefringence in bright soliton interactions in an optical fibre is investigated numerically. Groups containing up to five solit ons have been used as the input condition, with an angle psi being use d to determine the amplitudes of the resulting partial pulses in the s low (u) and fast (u) polarisation states. The concept of displacement length, xi(1), is used to characterise the interactions and general pl ots of the variation of this quantity with group velocity birefringenc e parameter, delta, and interpulse separation, are presented. Both a m inimum and a maximum are found. Unequal amplitudes acid interpulse pha se differences are also investigated. Amplitude variations are shown t o be effective in improving xi(1) but phasing has a negative effect. F inally, shadow amplitudes for pairs of solitons in the u and u states are given as a general function of offset and interpulse parameters.