Development of Single Crystal Barium Sodium Niobate as a Nonlinear Optical Material

摘要

Growth of barium sodium niobate single crystals by the Kyropoulos and Czochralski techniques is reported. Methods for growing single crystals under low thermal gradient conditions by the Czochralski technique are described in detail. Large c-axis boules were produced free of strain, scatter, and striae. Apparatus and techniques were developed for simultaneously poling and detwinning the crystals. Crystals grown from melts of standard, near stoichiometric, composition developed color centers. Crystals grown from niobium-deficient compositions were colorless, but highly strained. Fringe counts, transmittance as a function of applied electric field, second harmonic generation tests, and absorption measurements are described and the results are tabulated for crystals of three different compositions. Physical measurements and boule quality are correlated. (Author)