Results are presented for generation of 1064 nm and 1573 nm outputs using a common ring resonator for a laser diodeside-pumped zig-zag geometry Nd:YAG laser slab and three NCPM (non-critically phase-matched) KTP crystals. The performance of the resonator at each wavelength is reported, for various configurations. First a common resonator was tested, then a separate resonator was used to gain an understanding of the performance variation with resonator length and OPO output coupling. A second common resonator was then tested, which had an optimized configuration to improve its efficiency. The conversion efficiency of the final design was 35% with 29 mJ output at 1573 nm wavelength for 83 mJ at 1064 nm.
A laser diode end-pumped Q-switched Nd:YVO<sub>4</sub> laser operating over a 25% to 100% duty cycle range has been built and characterised. A maximum average output power of 24.5 W has been achieved at an optical-to-optical conversion efficiency of 43%, with a beam quality factor M<sup>2</sup> of 1.1.