Fabrication of very high quality periodically poled KNbO/sub 3/ for efficient second-harmonic generation

We report on the fabrication of very high quality periodically poled KNbO/sub 3/ with dimensions of 3/spl times/4/spl times/0.925 (a/spl times/b/spl times/c) mm/sup 3/ and a period of 32.5 /spl mu/m for second-harmonic generation.