Second-harmonic generation in highly textured LiNbO3 films prepared by pulsed laser deposition

摘要

LiNbO3 films have been deposited on (001) sapphire substrates by pulsed laser deposition, in an oxygen environment. Films grown at substrate temperatures of 650°C are crystalline, strongly textured, and show a degree of twining that is lower the higher the oxygen pressure is in the range of 0.5-1 Torr. Values of the nonlinear optical coefficients d33 and d31 of the films, measured via second-harmonic generation, are close to those for the bulk LiNbO3 single crystal. The dependence of both the degree of twining and the nonlinear optical response on the film thickness suggests that the films become closer to single domain for larger thickness. © 2000 American Institute of Physics.