“…Later, inspired by nondegenerate solitons, more general nondegenerate Kuznetsov-Ma breathers [12] and nondegenerate Akhmediev breathers [13,14] have also been studied. In recent years, based on several different mathematical physics methods such as the Hirota bilinear method, Kadomtsev-Petviashvili hierarchy reduction and developing Darboux transformation method, nondegenerate solitons have been reported in various multi-mode fiber systems, such as the Manakov systems, [15][16][17] generalized coupled nonlinear Schrödinger systems, [18][19][20][21][22] long-wave shortwave resonant interaction systems, [23] and coupled Fokas-Lenells systems. [24] Generally speaking, to describe the propagation of beams in two polarized directions, coupled nonlinear Schrödinger (CNLS) equations [25] iu z + 1 2 u tt + (|u| 2 + |v| 2 )u = 0, (1a)…”