The pulse shape from the pulsed amplifier always distorts because of gain saturation effect, an effective method is active control the output pulse shape by reshaping the pulse shape of the laser seed. We demonstrated a new method for active temporal pulse shape control of fiber amplifier with adaptive proportional control. We numerically researched three proportional control methods, including static proportional control, adaptive proportional control and piecewise adaptive proportional control. The results show that proportional control can generate arbitrary temporal pulse shape with high accuracy and less iterations even if parameters of the fiber amplifier are unknown.
A novel method for active coherent beam combining by Particle Swarm Optimization (PSO) algorithm is demonstrated in this paper. The principle of this method is introduced, and its advantages are presented in detail. In the simulation, 37 fiber lasers are coherently combined by employing stochastic parallel gradient descent algorithm with 91 steps, and then, the combined beams are combined by PSO algorithm with only 30 steps. And the result shows that the more laser elements, the more remarkable PSO algorithm is in the CBC system. Because of the high control ability of PSO algorithm in coherent beam combining combined with traditional algorithm, it is scalable to phase-locking system in a large number of fiber lasers.