Role of modulation frequency in a hybrid Q-switched Nd:LuVO₄ laser with an acousto-optic modulator and a Cr⁴⁺:YAG saturable absorber.

This study presents a hybrid Q-switched Nd:LuVO₄ laser with an acousto-optic modulator (AOM) and a Cr⁴⁺:YAG saturable absorber. The importance of the modulation frequency of the AOM in this dual-loss modulation system is examined with two distinct observations: (1) the periodic-ramp pulse characteristics with the modulation frequency, and (2) the existence of the intrinsic modulation frequency for minimizing the pulsewidth. The shortest pulsewidth and the highest peak power were 10.6 ns and 13.9 kW, respectively, at a pump power of 10 W. Compared with the passively Q-switched laser, which has a pulsewidth of 18.3 ns, the ratio of pulse compression reaches 42%. Finally, numerical simulations based on the rate equations are used to verify the experimental results.