Ultraviolet-infrared laser-induced domain inversion in MgO-doped congruent LiNbO 3 and near stoichiometric LiTaO 3 crystals

Abstract

Laser-induced domain inversion is a promising technique for domain engineering in LiNbO 3 and LiTaO 3 . The ultraviolet-infrared laser induced domain inversions in MgO-doped congruent LiNbO 3 and near stoichiometric LiTaO 3 crystals are investigated for the first time here. Within the wavelength range from 351 to 799 nm, the different reductions of nucleation field induced by the focused continuous laser irradiation are systematically investigated in the MgO-doped congruent LiNbO 3 crystals. The investigation of ultrashort-pulse laser-induced domain inversion in MgO-doped congruent LiNbO 3 is performed with 800 nm wavelength irradiation. The focused continuous ultraviolet laser-induced ferroelectric domain inversion in the near stoichiometric LiTaO 3 is also investigated. The different physical explanations, based on space charge field and defect formation, are presented for the laser-induced domain inversion, and the solid experimental proofs are also presented. The results provide the solid experimental proofs and feasible schemes for the further investigation of laser-induced domain engineering in MgO-doped LiNbO 3 and near stoichiometric LiTaO 3 crystals. The important characteristics of domain inversion, including domain wall and internal field, in LiNbO 3 crystals are also investigated by the digital holographic interferometry with an improved reconstruction method, and some creative experimental results and conclusions are achieved.