Synchronized actively Q-switched Nd:YAG laser generating 3 W average power at 589 nm

This paper presents a scheme for generating high-peak power pulsed light at 589 nm from a diode-pumped solid state (DPSS) Q-switched laser system. The set-up utilized two individually pumped Nd:YAG crystals, generating light at 1064 nm and 1319 nm respectively. The cavity of the laser system consisted of two individual sections for each Nd:YAG crystal, and a common section. In the common section an acousto-optical Q-switch switching both lines simultaneously was inserted. Both crystals were end-pumped by a 30 W 808 nm fiber coupled diode laser. By carefully modeling and designing the cavity parameters and pump spot sizes in the individual Nd:YAG crystals synchronization of the pulses on the two lines could be achieved with approximately equal pump powers. Fine tuning of the synchronization was then achieved through adjusting the pump power delivered to the individual crystals.