128 mJ/Pulse, Laser-Diode-Pumped, Q-Switched Tm:YAG Laser

We demonstrated a high-pulse-energy, laser-diode-pumped Tm:YAG laser in AO Q-switched operation. In laser experiments, we introduced a composite-type Tm:YAG laser rod with undoped endcaps. The rod was pumped by 785-nm quasi-continuous-wave laser diodes in a side-pumping configuration. To obtain a high energy and high beam quality, we designed a Tm:YAG laser cavity utilizing the thermal lens effect of the laser rod. A Q-switched output energy of 128 mJ at 10 Hz with a pulse width of 160 ns was obtained from the laser oscillator at room temperature, and the slope efficiency reached 14%. A high beam quality in the TEM
₀₀
mode was also realized.