Pulse Splitting Induced by Higher-Order Saturable Absorption Effects in Fiber Lasers

In fiber laser systems, the accumulation of excessive nonlinear phase shifts has been conventionally regarded as the primary mechanism leading to pulse splitting. Through numerical simulations, we demonstrate that higher-order saturable absorption effects—particularly reverse saturable absorption—can also induce pulse splitting phenomena. By implementing a deliberately designed dissipative cavity configuration, we successfully distinguish the characteristic differences between pulse splitting induced by reverse saturable absorption and that caused by nonlinear phase shift accumulation.