Summary form only given. To generate the UV harmonics of the microchip laser output, we used antireflection-coated pieces of BaB/sub 2/O/sub 4/ oriented for type-I phase matching. In all cases, the crystals were 5-mm long, had flat faces, and were placed in the output path of the Nd:YAG laser with nointervening optics. The 532-nm green radiation was doubled to produce 266-nm UV radiation with 20% energy efficiency.