采用反射式达曼光栅对飞秒激光进行分束,可以避免材料色散的影响。搭建了利用反射式1×2达曼光栅为基础的频率分辨光学开关(FROG)装置,并把测量结果与传统多发频率分辨光学开关装置的测量结果进行了对比。理论和实验结果表明,当输入脉冲宽度大于50 fs时,用达曼光栅作为分光器和使用分光镜分光的效果是一样的;当输入脉冲的宽度小于50 fs时,用达曼光栅作为分光器引入的展宽量明显小于分光镜引入的展宽量,尤其是当输入脉冲的宽度小于20 fs时用达曼光栅作为分光器的效果更为突出。

A 1×2 array Dammann grating beam splitter for implementation of frequency resolved optical gating (FROG) is proposed. Beam splitting with Dammann grating can avoid the material dispersion in traditional beam splitters. The measuring result by the newly established FROG is compared with that of a traditional multi-pulse FROG. Theoretical and experimental results show that when the input pulse width is larger than 50 fs, the pulse broadening introduced by Dammann grating and general beam splitter is almost identical; but when the input pulse is shorter than 50 fs, the broadening effect of Dammann grating is obviously less than that introduced by general beam splitter, especially for laser pulses shorter than 20 fs.