单程拼接光栅压缩池系统中光栅缝隙的衍射效应

利用傅里叶光学方法，建立了一个基于远场的高斯光束数学模型.该模型能够分析单程拼接光栅压缩池系统中拼接光栅的缝隙对远场时空特性的影响.数值模拟得到了不同系统参数时远场时空特性关于缝隙宽度的变化曲线.揭示了光栅缝隙对远场的影响规律：对于双光栅拼接的压缩池系统，若只是压缩池中第二块光栅为拼接光栅，则光栅缝隙导致远场时域略微变窄；若压缩池中的两块光栅都是拼接光栅，则缝隙导致远场时域展宽或者变窄，依赖于入射脉冲的傅里叶变换极限型脉宽大小；光栅缝隙对于远场强度分布的影响是导致中央主峰能量下降，并且出现两个子峰，子峰的峰值随缝宽的增大而增大.

Diffraction effect of the seams between the segmented gratings in a single-pass tiled-grating compressor

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.