Abstract: | In this paper, we report that mode-locked operation is realized in a flashlamp-pumped Nd:YAG laser with a nearly critical stable resonator, using LiF:F2− color center crystal as a modulation device. A single pulse train with the energy of 25 mJ and the pulse duration of 82 ps is obtained. Both the theoretical and experimental results have shown that the mode-locked operation has resulted from kerr-lens effect formed in combination with self-focusing within Nd:YAG and an aperture at a specific point, but not directly from the saturable absorption of LiF:F2− crystal. |