Influence of amplitude and phase fluctuations on the characteristics of a mode-locked laser pulse train

The Fourier transform method has been used to analyze the influence of modal amplitude and phase fluctuations in a mode-locked laser on performance of its output pulse. The results show that the pulse shape and the bandwidth remain essentially constant when the modes have amplitude and phase fluctuations, but appear superimposed on a fluctuations background. The phase variations will cause the fluctuation of peak. The physical picture in this paper is concise and is helpful to get stable mode-locked laser output in experiments.