Liquid phase epitaxial growth of LiNbO3 thin film using Li2O-B2O3 flux system
1993; Elsevier BV; Volume: 132; Issue: 1-2 Linguagem: Inglês
10.1016/0022-0248(93)90246-s
ISSN1873-5002
AutoresAtsuo Yamada, H. Tamada, Masaki Saitoh,
Tópico(s)Advanced Fiber Laser Technologies
ResumoLiNbO3 thin film optical waveguides were fabricated by liquid phase epitaxy. In order to improve the crystallinity and optical transparency of the film, a 5 mol% MgO-doped LiNbO3 substrate and Li2O-B2O3 flux system were used instead of a conventional combination of LiTaO3 substrate and Li2O-V2O5 flux system. Dependence of film properties on the melt composition was investigated in detail. As a result, high crystallinity with a small linewidth of 11.4 arc sec in the X-ray rocking curve, and good surface morphology with perfect mirror surface were realized by choosing a suitable melt composition. The chemical composition of the grown film was estimated to be nearly stoichiometric from results of several characterizations, and the Li/Nb ratio of the film could not be widely changed by changing the Li2O/Nb2O5 ratio in the melt. The as-grown film shows a perfect transparency for the wavelength down to the fundamental absorption edge resulting in a small guided optical wave propagation loss of less than 1 dB/cm at a wavelength of 458 nm. Ferroelectric domain inversion phenomena at the film-substrate interface, and preliminary results of trial on controlling film properties by Mg, Zn, Na and Ti doping are also shown and discussed.
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