Study on satellite pulse characteristics of LD-end pumped sub-nanosecond Nd:YAG/Cr4+:YAG oscillator

Miniaturized sub-nanosecond laser is critical to the applications such as medical treatment, Lidar and manufacturing. In this paper, a high repetition rate hundred picosecond pulse oscillator based on Nd:YAG/Cr4+:YAG bonded crystal is demonstrated, and its output pulse characteristics are studied. It is found that the stability of amplitude and frequency of Q-switched pulse can be improved effectively by pulsedpumping. A satellite-free sub-nanosecond laser with a pulse width of 663 ps and an average power of 80 mW at the repetition rate of 1 kHz was developed, while the 50 μs pulse width of the pump was employed. Meanwhile, the near-diffraction limit output beam (M2 =1.03 ± 0.02) with pulse energy instability of less than 2 % was obtained. This study provides a reference for the development of highly stable satellite-pulse-free passive Q-switched lasers with a high repetition rate.