The Curie temperature, birefringence, and phase-matching temperature of LiNbO3 are shown to vary with the stoichiometry of the melt from which the crystals are pulled. The range of melt stoichiometry, indexed by the Li/Nb mole ratio, was varied from 1.20 to 0.80. This Li/Nb variation changes the Curie temperature, refractive index for the extraordinary ray, and the phase-matching temperature by 120°C,.03, and 320°C respectively. The relevance of these changes are discussed in terms of the susceptibility of LiNbO3 to index inhomogeneities.
Bergman et al. (Thu,) studied this question.