Laser diode-pumped low timing jitter saturable output coupler Q-switched microchip laser: simulations and experiments

Abstract

We studied the pulsed laser diode (LD)-pumped saturable output coupler (SOC) passively Q-switched Nd:YVO4 transmission microchip laser both numerically and experimentally. We demonstrated numerically that the timing jitter decreased with increasing pump power both in the continuous wave (CW) LD pump scheme and the pulsed LD pump scheme. Compared with the CW pump scheme, the pulsed LD pump scheme showed a better performance in timing jitter control due to the much higher peak power and shorter duration of the pulses. Experiments were also carried out to verify the theoretical analysis results. As the pump power of the CW LD increased, the timing jitter value of our laser decreased from 1.68% at 30 mW pump power to a constant around 0.86% at 90 mW. The output frequency can be controlled by changing the pump spot size in the rectangular shape pulsed pump scheme, and it was achieved from 333.3 to 71.4 kHz, while the relative timing jitter decreased from 0.10% to 0.03% accordingly. Additionally, the microchip laser had a good stability of output power, and the power fluctuation was below 2% in a 2-h measurement.