Pump pulse characteristics of quasi-continuous-wave diode-side-pumped Nd:YAG laser

The influence of pumping laser pulse on the property of quasi-continuous-wave (QCW) diode-side-pumped Nd:YAG laser is investigated theoretically and experimentally. Under remaining a fixed duty cycle, the average output power increases, and the corresponding thermal focal length shorten with the increase of the pump pulse duration, which attributes to the decrease of the ratio of pulse buildup time to the pulse duration. At a pump power of 146 W, the laser output power changes from 65.1 W to 81.2 W when the pulse duration is adjusted from 150 mu s to 1000 mu s, confirming a significant enhancement of 24.7%. A laser rate equation model incorporating the amplified spontaneous emission is also utilized and numerically solved, and the simulated results agree well with the experimental data.