Stability of quadrupole solitons in nonlocal media

Abstract

We study quadruple-mode (quadrupole) solitons in nonlocal media with different degrees of nonlocality. The existence and stability of such quadrupole solitons is addressed systematically. The solution of quadrupole solitons is obtained analytically with variational approach. The propagation dynamics of quadrupole solitons is found numerically with the split-step method. The repulsion between the out-of-phase petals of quadrupole solitons can not be balanced by the weak nonlocality, leading to the formation of four separated scalar solitons. Completely stable quadrupole solitons can be achieved when the nonlocality is strong.