INTERACTION BETWEEN SOLITONS IN BIREFRINGENCE FIBER

The single-mode fiber can preserve two orthogonal polarized degenerate modes([1]). Two orthogonal modes have no coupling when the fiber has a strict cylinder shape or the material is isotropic under ideal fiber condition. But in real fiber, the degenerate mode is destroyed by the deflection from strict cylinder shape and the slight fluctuation of anisotropy of material, which causes the mixture of two polarization states and brings about birefringence([2,3]). As a result of the birefringence, the interaction between solitons in fiber is generated, and the bound soliton state may even be formed([4]). The interaction between solitons will certainly decrease the transmission rate and increase the bit error rate in soliton communication system([5-7]). How to effectively control the interaction between solitons is a critical problem in optical soliton communication system. In this note, we study the interaction between solitons in birefringence fiber by using Lagrange-Euler's formula, and get some significant results.