Pulse-jitter reduction in passively Q-switched Nd:YAG/Cr:YAG microchip lasers by injection seeding actively Q-switched laser pulses

In order to obtain a passively Q-switched sub-nanosecond microchip laser with a low pulse jitter of less than 10 ns, a scheme of injection-seeding stable nanosecond laser pulses was designed. The pulse timing jitter of the passively Q-switched laser was improved from μs-level to ns-level with the seeding pulse energy of around 70 μJ. Based on experimental measurements, the dynamic process of pulse locking by varying the seeding pulse energy was discussed. The locking threshold affected by the peak pump power and time delay (Δt_Q) between the initial passively Q-switched laser and seeding pulses was also analyzed.