High-repetition-rate Q-modulation in solid-state laser using fast saturable absorber V:YAG

A high-repetition-rate Q-modulation operation in a solid-state Nd:GdVO₄ laser with a V³⁺:YAG saturable absorber has been demonstrated in this paper. The V³⁺:YAG crystal behaves as a fast saturable absorber in this laser because of its very short lifetime of 22 ns. Taking advantage of such fast bleaching recovery and effective cooling of the V:YAG by a home-made copper holder, we realized a pulse repetition rate of 2.4 MHz, which is, to our best knowledge, the maximum among the reported passively Q-switched lasers. The corresponding average output power and pulse width were 1.28 W and 170 ns, respectively, giving a slope efficiency of 15.9% and a pulse energy of 0.53 µJ. This compact high-repetition-rate Q-switched laser offers a potential application in the construction of low-cost, integrated and portable sensing detection equipment which needs a high laser pulse repetition rate. (paper)