NONLEAKY OPTICAL WAVE-GUIDES IN KNBO3 BY ULTRALOW DOSE MEV HE ION-IMPLANTATION

Planar optical waveguides in single crystals of KNbO3 were produced by 1 and 2 MeV He ion implantation with doses between 5 X 10(13) and 5 X 10(14) cm-2. We observe nonleaky waveguiding due to an implantation induced increase of n(c), the smallest of the three refractive indices of KNbO3. For 2 MeV He ions and a dose of 10(14) cm-2 waveguides with typical propagation losses of approximately 3 dB/cm have been fabricated. The possibility of producing nonleaky waveguides by ultralow dose implantation promises the creation of complicated channel waveguide structures within minutes.