High-power diffraction-limited Nd:YVO4 continuous-wave lasers at 1.34 μm

We describe the development of Nd:YVO
₄
lasers with continuous-wave emission at 1.342 μm; they contain either one or two crystals which are longitudinally pumped by fiber-coupled diode laser arrays. With a single crystal, the output power is 7.3 W, while with the twin crystal configuration the power reaches 12 W. The best slope efficiency is 40% and the output beam divergence is about two times the diffraction limit. The influence of the Nd concentration, of the pump spot-size, and of the resonator configuration have been experimentally studied. Data on the thermally induced lens are also reported and discussed.