摘要

By using Fourier optics, a model based on the far field about the Gauss pulse is set up, by which the effect of seams on the far field can be studied. Numerical simulation shows that pulse-width narrowing will appear in the case of single seam and the Fourier-translation-limited pulse-width of the input pulse will determine whether the pulse width in the far field becomes narrow or broad. In addition, the irradiance in the focus decreases and two sub-peaks appear beside the central peak, and their intensties increase with the widening of seams.