Controlling Chaos in A Dual-Ring Erbium-Doped Fiber Laser by Modulating The Pump

Control of chaos in a dual-ring erbium-doped fiber laser is studied by modulating the laser pump and its physical model is presented to induce the dual-ring erbium-doped fiber laser to a cyclic state and other dynamics states via adding a periodic signal to the pump. When one pump is modulated by a periodic square wave signal, we find that chaotic behaviors of the laser can be pressured and the dual-ring can show two periodic states while each ring can emit cyclic pulses. It indicates that chaotic dual-ring erbium-doped fiber laser has been controlled. When another periodic square wave signal with a different modulation depth value is used to perform on the laser, behavior of the laser can be deduced to produce multi-periodic states. When the pump is modulated by a sinusoidal signal, behaviors of the laser can be controlled to deduce two other periodic states while each ring emits cyclic pulses. We find that chaotic behavior of the laser can be controlled. And the laser shows a lot of dynamics behaviors via the chaos-control method. The result is very helpful to study of chaos-control techniques, fiber lasers and other lasers.