Properties to Characterize Undoped and Optical-Damage-Resistant LiNbO₃ Crystals

Summary

Many properties, relevant to the topics of this monograph depend on the composition of lithium niobate and tantalate. In an overview, we mention and evaluate, methods to determine the composition of the melt and the crystal. Emperical equations are given to estimate the crystal composition from that of the melt. Besides the measurement of the Curie temperature the position of the UV absorption edge can serve as a sensitive method for an accurate determination of the composition. The main topics of this section are the refractive index and birefringence including the modeling by various Sellmeier equations as a function of wavelength, composition, doping, and temperature. The phase-matching temperature and angle in the context of second-harmonic-generation are discussed as well as one other nonlinear feature, the electro-optic effect in lithium niobate doped with damage-resistant impurities.