Perturbation Theory for Optical Soliton

Based on the main idea of the derivative expansion method, a perturbation approach is proposed for the investigation of single soliton propagating down a nonideal monomode optical fiber. This approach is totally independent of inverse scattering theory, which has substantial difference from the past methods. In this scheme, the first-order correction is derived by the method of eigenfunction expansion, and the parameters change is directly obtained from the secularity conditions for some cases.