Ferroelectric integrated optics: recent developments

Advances in rare-earth-doped waveguide lasers in LiNbO/sub 3/, waveguided second harmonic generation through quasi-phase-matching in LiNbO/sub 3/ and LiTaO/sub 3/, and pulsed laser epitaxial growth of LiNbO/sub 3/ on Sapphire are reported. Efficient lasers operating in CW, Q-switch, and mode-lock modes were fabricated in Nd:LiNbO/sub 3/. In order to assess the potential of bulk-doped Er:LiNbO/sub 3/ samples, spectroscopic measurements have been carried out, the main limiting mechanism identified, the corresponding up-conversion coefficient evaluated, and a comprehensive gain model developed. First lasing action in this material, when pumped at 1.48 /spl mu/m, is described. Quasi-phase-matched generation of blue light with conversion efficiencies up to 150%/Wcm/sup 2/ is also demonstrated, and finally we present the fabrication of low-loss LiNbO/sub 3/ single-crystal waveguiding layers.