LiNbO/sub 3/ epitaxial films on c-sapphire substrates for waveguide applications

Summary form only given. LiNbO/sub 3/ (LN) waveguide devices play a very important role in many areas of optical communications and are expected to be used for various applications such as wavelength conversion devices, waveguide lasers, etc. Such waveguide devices are normally made by impurity diffusion into bulk LN crystals, though the optical confinement and interface abruptness of such devices need improvement. Heteroepitaxially grown LN on the substrates with lower refractive index than LN can make possible good confinement of optical energy. High performance optical devices can be fabricated provided that the techniques to grow high-quality LN films are developed. In this work, we report the growth and characterization of the heteroepitaxial growth of LN films on sapphire (/spl alpha/-Al/sub 2/O/sub 3/) substrates. Methods to improve film quality and the correlation between the crystalline and the optical properties will be discussed.