Vector combined and crossing Kuznetsov–Ma solitons in $$\mathcal {PT}$$ PT -symmetric coupled waveguides

Abstract

A variable-coefficient coupled nonlinear Schrodinger equation with balanced gain and loss is studied, and two kinds of analytical Kuznetsov–Ma soliton solutions including combined Kuznetsov–Ma soliton solution and crossing two-Kuznetsov–Ma soliton solution are obtained. In a diffraction decreasing system, the control for the excitation of two kinds of Kuznetsov–Ma soliton including rear excitation, peak excitation and initial excitation is investigated. The different peak locations of Kuznetsov–Ma soliton along the propagation direction appear repeatedly, which makes rear excitation, peak excitation and initial excitation happen again and again.