Higher-order nonlinear effects on optical soliton propagation and their interactions

When pursuing femtosecond-scale ultrashort pulse optical communication, one cannot overlook higher-order nonlinear effects. Based on the fundamental theoretical model of the variable coefficient coupled high-order nonlinear Schrödinger equation (VCHNLSE), this paper explores the evolution of optical solitons in the presence of high-order nonlinear effects analytically. Besides, the interactions between two nearby optical solitons and the transmission of them in a nonuniform fiber are investigated. The stability of optical soliton transmission and interactions are found to be destroyed to varying degrees due to higher-order nonlinear effects. The outcomes will offer some theoretical references for achieving ultra-high energy optical solitons in the future.