Evaluation of hydroxyl content in commercial <inline-formula>X</inline-formula>-cut <inline-formula><roman>LiNbO</roman><sub><roman>3</roman></sub></inline-formula> wafers for optical waveguide devices

Abstract

Usually the quality of commercial LiNbO3 (LN) wafers is checked by their crystalline homogeneity. In X cut wafers, which are labeled for optical waveguide applications, however, the existence of a significant change in the hydroxyl content along the polarizedZ axis is found by Fourier transform IR (FTIR) spectrometry, although a corre- sponding inhomogeneity was not observed about the lattice parameters, the Li and Nb contents, and the optical birefringence parameters. Such a difference in hydroxyl content might influence quality and stability of the obtained waveguides, and one should consider this before designing waveguide devices and fabrication processes. © 1998 Society of Photo- Optical Instrumentation Engineers. (S0091-3286(98)01905-9)