Phonon Spectra And Electro-Optic Properties Of Crystalline Phases In Proton-Exchanged Litao3 Wave Guides

Annealed proton-exchanged wave guides in X-cut LiTaO3 were characterized by infrared reflection and Raman scattering spectroscopy. The measured spectra were related to the multiple crystalline phases of HxLi1-xTaO3 as identified by direct wave guide index profiling. Unique relationships were found to exist between the crystalline phases and corresponding spectra, which thus can be used to identify phase contents in a given wave guide. Vibrational bands of the studied spectra were correlated with the electro-optic properties of HxLi1-xTaO3 phases. Phase-dependent anisotropy of protonic conductivity was predicted based on the observed polarization dependence of OH libration bands. Finally, the electro-optic coefficient r(33) was theoretically estimated for all phases and compared with previously reported experimental data. (C) 2002 American Institute of Physics.