Fig. 1. Experimental setup of off-axis pumped acousto-optic Q-switched laser, and spot radius of outmost spot of HG mode. (a) Experimental setup of off-axis pumped acousto-optic Q-switched laser; (b) radius of outmost spot of HG mode

Fig. 2. Off-axis displacement, threshold pump power, and pattern of HG_16,0 mode. (a) Off-axis displacement; (b) threshold pump power; (c) pattern of HG_16,0 mode

Fig. 3. Mode hopping occurs when pump power increases. (a) HG_2,0 hopping to HG_1,0; (b) HG_3,0 hopping to HG_2,0; power fluctuations (c) before mode hopping, (d) in mixed mode state, and (e) after mode hopping

Fig. 4. Pump power of HG modes for mode hopping

Fig. 5. Variation in correction value of off-axis displacement with pump power

Fig. 6. Output power of HG modes. (a) Power varying with pump power; (b) power of each HG mode for pump power of 3.1 W

Fig. 7. Decrease in effective off-axis amount caused by off-axis thermal lens

Fig. 8. Output pulse train and pulse shape at maximum output power. (a) Pulse train; (b) pulse shape

Fig. 9. Pulse width and peak power of HG modes. (a) Pulse width; (b) peak power